0001493152-23-025878 | 10-K | XBRL Viewer | Ocean Power Technologies INC

Inventory (Tables)

12 Months Ended

Apr. 30, 2023

The Company holds inventory related to the production of our products.

Schedule of Inventory

	April 30, 2023		April 30, 2022
	(in thousands)
Raw Materials	$	1,044	$	198
Work in Process		—		244
Inventory, net	$	1,044	$	442

Consolidated Balance Sheets - USD ($) $ in Thousands	Apr. 30, 2023	Apr. 30, 2022
Current assets:
Cash and cash equivalents	$ 6,883	$ 7,885
Short-term investments	27,790	49,384
Restricted cash, short-term	65	258
Accounts receivable	745	482
Contract assets	152	386
Inventory	1,044	442
Other current assets	994	467
Total current assets	37,673	59,304
Property and equipment, net	1,280	445
Intangibles, net	3,978	4,136
Right-of-use assets, net	1,751	752
Restricted cash, long-term	155	219
Goodwill	8,537	8,537
Total assets	53,374	73,393
Current liabilities:
Accounts payable	952	905
Earn out payable	1,500
Accrued expenses	2,346	877
Contract liabilities	1,378	129
Right-of-use liabilities, current portion	529	319
Contingent liabilities, current portion	1,202	748
Total current liabilities	7,907	2,978
Deferred tax liability	203	203
Contingent liabilities, less current portion		843
Right-of-use liabilities, less current portion	1,311	538
Total liabilities	9,421	4,562
Shareholders’ Equity:
Preferred stock, $0.001 par value; authorized 5,000,000 shares, none issued or outstanding
Common stock, $0.001 par value; authorized 100,000,000 shares, issued 56,304,642 and 55,905,213 shares, respectively, and outstanding 56,263,728 and 55,881,861 shares, respectively	56	56
Treasury stock, at cost; 40,914 and 23,352 shares, respectively	(355)	(341)
Additional paid-in capital	324,393	322,932
Accumulated deficit	(280,096)	(253,770)
Accumulated other comprehensive loss	(45)	(46)
Total shareholders’ equity	43,953	68,831
Total liabilities and shareholders’ equity	$ 53,374	$ 73,393

Subsequent Events (Details Narrative) - USD ($)	Jun. 29, 2023	Jun. 01, 2023	Nov. 15, 2021
Subsequent Event [Member]
Subsequent Event [Line Items]
Number of value issued		$ 500,000
Number of value issued, shares		1,923,077
Common Stock [Member]
Subsequent Event [Line Items]
Number of value issued			$ 4,000,000
Number of value issued, shares			3,330,162
Sale of Stock, Number of Shares Issued in Transaction			3,330,162
Common Stock [Member] \| Subsequent Event [Member]
Subsequent Event [Line Items]
Number of value issued, shares	2,403,846
Common Stock [Member] \| Subsequent Event [Member] \| Earnout Provisions [Member]
Subsequent Event [Line Items]
Number of value issued, shares	1,923,077
Common Stock [Member] \| Subsequent Event [Member] \| Performance Bonuses [Member]
Subsequent Event [Line Items]
Number of value issued, shares	480,769

- Definition

Equity impact of the value of new stock issued during the period. Includes shares issued in an initial public offering or a secondary public offering.

+ References + Details

Cover - USD ($) $ in Millions	12 Months Ended
Cover - USD ($) $ in Millions	Apr. 30, 2023	Jul. 28, 2023	Oct. 31, 2021
Document Type	10-K
Amendment Flag	false
Document Annual Report	true
Document Transition Report	false
Document Period End Date	Apr. 30, 2023
Document Fiscal Period Focus	FY
Document Fiscal Year Focus	2023
Current Fiscal Year End Date	--04-30
Entity File Number	001-33417
Entity Registrant Name	Ocean Power Technologies, Inc.
Entity Central Index Key	0001378140
Entity Tax Identification Number	22-2535818
Entity Incorporation, State or Country Code	DE
Entity Address, Address Line One	28 ENGELHARD DRIVE
Entity Address, Address Line Two	SUITE B
Entity Address, City or Town	MONROE TOWNSHIP
Entity Address, State or Province	NJ
Entity Address, Postal Zip Code	08831
City Area Code	(609)
Local Phone Number	730-0400
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Public Float			$ 40.8
Entity Common Stock, Shares Outstanding		58,730,917
ICFR Auditor Attestation Flag	false
Document Financial Statement Error Correction [Flag]	false
Auditor Firm ID	274
Auditor Name	EisnerAmper LLP
Auditor Location	Iselin, New Jersey
Common Stock Par Value 0.001 [Member]
Title of 12(b) Security	Common Stock, par value $0.001
Trading Symbol	OPTT
Security Exchange Name	NYSE
Series A Preferred Stock Purchase Rights [Member]
Title of 12(b) Security	Series A Preferred Stock Purchase Rights
Trading Symbol	n/a
Security Exchange Name	NYSE

Schedule of Components of Intangible Assets (Details) - USD ($) $ in Thousands	Apr. 30, 2023	Apr. 30, 2022
Goodwill and Intangible Assets Disclosure [Abstract]
Patents	$ 2,729	$ 2,729
Trademarks	2,769	2,769
Tradename	130	130
Customer Relationships	150	150
Intangible assets, gross	5,778	5,778
Accumulated amortization	(1,800)	(1,642)
Intangible assets, net	$ 3,978	$ 4,136

Summary of Significant Accounting Policies

12 Months Ended

Apr. 30, 2023

Accounting Policies [Abstract]

Summary of Significant Accounting Policies

(2) Summary of Significant Accounting Policies

(a) Basis of Consolidation

The accompanying consolidated financial statements include the accounts of the Company and its majority-owned subsidiaries, Marine Advanced Robotics Inc. (CA), 3dent Technologies LLC (TX), and Ocean Power Technologies Ltd. in the United Kingdom. Also included are Ocean Power Technologies Pty Ltd. and Victorian Wave Power Pty. Ltd in Australia, which have been dissolved pending final tax clearance and Reed Sport OPT Wave Park, LLC (OR), which has been dissolved as of the filing of this document. All significant intercompany balances and transactions have been eliminated in consolidation.

(b) Use of Estimates

The preparation of the consolidated financial statements requires management of the Company to make several estimates and assumptions relating to the reported amounts of assets and liabilities at the date of the consolidated financial statements and the reported amounts of revenues and expenses during the period. Significant items subject to such estimates and assumptions include, among other items, stock-based compensation, valuation consideration related to business combinations, including contingent consideration, and other assumptions and estimates used to evaluate the recoverability of long-lived assets, goodwill and other intangible assets. Actual results could differ from those estimates.

(c) Business Combinations

The Company accounts for business combinations in accordance with Financial Accounting and Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) No. 2015-16, Business Combinations (Topic 805). The Company allocates the fair value of consideration transferred in a business combination to the estimated fair value at the acquisition date of the tangible and intangible assets acquired as well as the liabilities assumed. Acquisition costs are expensed as incurred. Any excess consideration transferred is recorded as goodwill and in instances where the fair value of consideration transferred is less than the estimated fair value of tangible and intangible assets acquired less liabilities assumed; such amounts are recorded as a gain on the bargain purchase.

(d) Revenue Recognition

The Company accounts for revenue in accordance with Accounting Standards Codification 606 (ASC 606) for contracts with customers and Accounting Standards Codification 842 (ASC 842) for leasing arrangements. In relation to ASC 606, which states that a performance obligation is the unit of account for revenue recognition, the Company assesses the goods or services promised in a contract with a customer and identifies as a performance obligation as either: a) a good or service (or a bundle of goods or services) that is distinct; or b) a series of distinct goods or services that are substantially the same and that have the same pattern of transfer to the customer. A contract may contain a single performance obligation or multiple performance obligations. For contracts with multiple performance obligations, the Company allocates the contracted transaction price to each performance obligation based upon the relative standalone selling price, which represents the price the Company would sell a promised good or service separately to a customer. The Company determines the standalone selling price based upon the facts and circumstances of each obligated good or service. When no observable standalone selling price is available, the standalone selling price is generally estimated based upon the Company’s forecast of the total cost to satisfy the performance obligation plus an appropriate profit margin.

The nature of the Company’s contracts may give rise to several types of variable consideration, including unpriced change orders, liquidated damages and penalties. Variable consideration can also arise from modifications to the scope of services. Variable consideration is included in the transaction price to the extent it is probable that a significant reversal of cumulative revenue recognized will not occur once the uncertainty associated with the variable consideration is resolved. Our estimates of variable consideration and determination of whether to include such amounts in the transaction price are based largely on our assessment of legal enforceability, performance, and any other information (historical, current, and forecasted) that is reasonably available to us. There was no variable consideration as of April 30, 2023 or 2022. The Company presents shipping and handling costs, that occur after control of the promised goods or services transfer to the customer, as fulfillment costs in costs of goods sold and regular shipping and handling activities charged to operating expenses.

The Company recognizes revenue when or as it satisfies a performance obligation by transferring a good or service to a customer, either (1) at a point in time or (2) over time. A good or service is transferred when or as the customer obtains control. The evaluation of whether control of each performance obligation is transferred at a point in time or over time is made at contract inception. Input measures such as costs incurred are utilized to assess progress against specific contractual performance obligations for the Company’s services. The selection of the method to measure progress towards completion requires judgment and is based on the nature of the services to be provided. For the Company, the input method using costs incurred or labor hours best represents the measure of progress against the performance obligations incorporated within the contractual agreements. If estimated total costs on any contract project a loss, the Company charges the entire estimated loss to operations in the period the loss becomes known. The cumulative effect of revisions to revenue, estimated costs to complete contracts, including penalties, change orders, claims, anticipated losses, and others are recorded in the accounting period in which the events indicating a loss are known and the loss can be reasonably estimated. These loss projects are re-assessed for each subsequent reporting period until the project is complete. Such revisions could occur at any time and the effects may be material. During the fiscal year ended April 30, 2023 the Company recognized approximately $1.0 million in revenue related to performance obligations satisfied at a point in time and approximately $1.7 million in revenue related to performance obligation satisfied over-time.

The Company’s contracts are either cost-plus contracts, fixed-price contracts, time and material agreements, lease or service agreements. Under cost plus contracts, customers are billed for actual expenses incurred plus an agreed-upon fee.

The Company has two types of fixed-price contracts, firm fixed-price and cost-sharing. Under firm fixed-price contracts, the Company receives an agreed-upon amount for providing products and services specified in the contract, and a profit or loss is recognized depending on whether actual costs are more or less than the agreed upon amount. Under cost-sharing contracts, the fixed amount agreed upon with the customer is only intended to fund a portion of the costs on a specific project. Under cost sharing contracts, an amount corresponding to the revenue is recorded in cost of revenue, resulting in gross profit on these contracts of zero. The Company’s share of the costs is recorded as product development expense. The Company reports its disaggregation of revenue by contract type since this method best represents the Company’s business. For the fiscal years ended April 30, 2023 and 2022, the majority of the Company’s contracts were classified as firm fixed-price.

The Company’s revenue also includes revenue from certain contracts which do not fall within the scope of ASC 606, but under the ASC 842. At inception of a contract for those classified under ASC 842, the Company classifies leases as either operating or financing in accordance with the authoritative accounting guidance contained within ASC Topic 842, “Leases”. If the direct financing or sales-type classification criteria are met, then the lease is accounted for as a finance lease. All others are treated as operating leases. The Company recognizes revenue from operating lease arrangements generally on a straight-line basis over the lease term, or as agreed upon in-use days are utilized, which is presented in Revenue in the Consolidated Statement of Operations. The Company also enters into lease arrangements for its PowerBuoys® and Wave Adaptive Modular Vessels (“WAM-V®”) with certain customers. Revenue related to multiple-element arrangements is allocated to lease and non-lease elements based on their relative standalone selling prices or expected cost plus a margin approach. Lease elements generally include a PowerBuoy®, WAM-V®, and components, while non-lease elements, which the Company expects to become more prevalent, generally include engineering, monitoring and support services. In the lease arrangement, the customer may be provided with an option to extend the lease term or purchase the leased buoy or WAM-V® at some point during and/or at the end of the lease term.

As of April 30, 2023, the Company’s total remaining performance obligations, also referred to as contracted backlog, totaled $4.0 million. The Company expects to recognize approximately 97%, or $3.9 million, of the remaining performance obligations as revenue over the next twelve months.

Existing customers are subject to ongoing credit evaluations based on payment history and other factors. If it is determined that collectability of any portion of the contract value is not probable, an analysis of variable consideration will be performed using either the most likely amount or expected value method to determine the amount of revenue that must be constrained until the scenario causing the variability has been resolved.

The Company has elected to record taxes collected from customers on a net basis and does not include tax amounts in revenue or costs of revenue.

The Company’s contract assets and liabilities primarily relate to the timing differences between cash received from a customer in connection with contractual rights to invoicing and the timing of revenue recognition following completion of performance obligations. The Company’s accounts receivable balance is made up entirely of customer contract related balances.

The below table represents the total revenue recognized under ASC 606 and ASC 842 fiscal years ended April 30, 2023 and 2022:

	Fiscal year ended April 30, 2023						Fiscal year ended April 30, 2022
	ASC 606		ASC 842		Total		ASC 606		ASC 842		Total
	(in thousands)						(in thousands)
Product Line:
WAM-V	$	919	$	667	$	1,586	$	401	$	—	$	401
Buoy		269		—		269		379		—		379
Services		877		—		877		979		—		979
Total	$	2,065	$	667	$	2,732	$	1,759	$	—	$	1,759

Region:
North and South America	$	1,812	$	667	$	2,479	$	1,633	$	—	$	1,633
Europe		—		—		—		19		—		19
Asia and Australia		253		—		253		107		—		107
Total	$	2,065	$	667	$	2,732	$	1,759	$	—	$	1,759

(e) Cash and Cash Equivalents, Restricted Cash, Security Agreements and Investments

Cash and Cash Equivalents

The Company considers all highly liquid investments with an original maturity of three months or less when purchased to be cash equivalents. The Company invests excess cash in a money market account or in short term investments that are held-to-maturity. The following table summarizes cash and cash equivalents for the years ended April 30, 2023 and 2022:

	April 30, 2023		April 30, 2022
	(in thousands)
Checking and savings accounts	$	2,874	$	1,815
Money market account		4,009		6,070
Cash and cash equivalents	$	6,883	$	7,885

Restricted Cash and Security Agreements

The Company has a letter of credit agreement with Santander Bank, N.A. (“Santander”). Cash of $155,000 is on deposit at Santander and serves as security for a letter of credit issued by Santander for the lease of warehouse/office space in Monroe Township, New Jersey. This agreement cannot be extended beyond July 31, 2025 and is cancellable at the discretion of Santander.

Santander also issued one letter of credit to subsidiaries of Enel Green Power (“EGP”) pursuant to the Company’s contracts with EGP. A letter of credit was issued in the amount of $645,000 and was reduced to $323,000 in August 2020. The letter of credit was further reduced by an additional $258,000 in January of 2023, when the PB3 and its accompanying systems passed final acceptance testing. The remaining restricted amount of $65,000 will be released in January of 2024, which is 12 months after the buoy was fully deployed.

The following table provides a reconciliation of cash, cash equivalents and restricted cash reported within the Consolidated Balance Sheets that total to the same amounts shown in the Consolidated Statements of Cash Flows.

	April 30, 2023		April 30, 2022
	(in thousands)
Cash and cash equivalents	$	6,883	$	7,885
Restricted cash- short term		65		258
Restricted cash- long term		155		219
	$	7,103	$	8,362

Investments

During fiscal 2022, the Company acquired investment securities through Charles Schwab Bank. As of April 30, 2023 and 2022, their carrying value was approximately $27.8 million and $49.4 million, respectively. All short term investments consist of corporate bonds, government agency bonds, or U.S. Treasury Notes and Bonds, are investment grade rated or better, and mature within 12 months. The Company has the ability and the intention to hold all investments to maturity, and as such are classified as held-to-maturity investments and carried at amortized cost. The total recognized interest expense on the premium we paid for and discounts we received on the securities for the years ended April 30, 2023 and 2022 is approximately $122,000 and $58,000, respectively. Additionally, there has been no impairment on these investments.

The following table summarizes the Company’s short term investments as of April 30, 2023 and 2022:

	April 30, 2023						April 30, 2022
Category	Amortized Cost		Unrealized Gains (Losses)		Market Value		Amortized Cost		Unrealized Gains (Losses)			Market Value
	(in thousands)
Corporate Bonds	$	14,776	$	100	$	14,876	$	37,777	$	995		$	38,772
Government Bonds & Notes	$	9,188	$	33	$	9,221	$	9,076	$	(1,022	)	$	8,054
Government Agency	$	3,826	$	25	$	3,851	$	2,531	$	(11	)	$	2,520
Total Short Term Investments	$	27,790	$	158	$	27,948	$	49,384	$	(38	)	$	49,346

(f) Inventory

Inventory is stated at lower of costs or net realizable value applicable to goods on hand remaining after the matching of absorbed costs with concurrent revenues. in accordance with ASC 330. The Company has three classes of inventory; raw materials, work in process, and finished goods. Items remain in inventory until they are shipped to the customer, at which time the costs are transferred on a FIFO basis to cost of good sold, or moved to leased assets as applicable.

(g) Accounts Receivable

Accounts receivable is stated at the amount billed or billable to customers and are ordinarily due between 30 and 90 days after the issuance of the invoice. Receivables are reserved or written off based on individual credit evaluation and specific circumstances of the customer. The Company grants credit to its customers, generally without collateral, under normal payment terms (typically 30 to 60 days after invoicing). Generally, invoicing occurs after the related services are performed or control of the product has transferred to the customer. Accounts receivable represent an unconditional right to consideration arising from the Company’s performance under contracts with customers. The carrying value of such receivables represents their estimated realizable value.

(h) Property and Equipment

Property and equipment are stated at cost, less accumulated depreciation and amortization. Depreciation and amortization is calculated using the straight-line method over the estimated useful lives (three to ten years) of the assets. Leasehold improvements are amortized using the straight-line method over the shorter of the estimated useful life of the asset or the remaining lease term. Expenses for maintenance and repairs are charged to operations as incurred. Property and equipment is also reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of the asset may not be recoverable. Recoverability of assets to be held and used is measured by a comparison of the carrying amount of the asset to estimated undiscounted future cash flows expected to be generated by the asset. If the carrying amount of the asset exceeds its estimated future cash flows, then an impairment charge is recognized in the amount by which the carrying amount of the asset exceeds the fair value of the asset.

Description		Estimated useful life

Equipment		5-7 years
Computer equipment & software		3 years
Office furniture & fixtures		3-7 years
Leasehold improvements		Shorter of the estimated useful life or lease term
Leased WAM-V assets		10 years

(i) Foreign Exchange Gains and Losses

The Company maintains cash accounts that are denominated in British pound sterling. These amounts are included in cash, cash equivalents and restricted cash on the accompanying Consolidated Balance Sheets. Transactions denominated in a foreign currency may result in realized and unrealized foreign exchange gains or losses from exchange rate fluctuations, which are included in “Foreign exchange (loss)/gain” in the accompanying Consolidated Statements of Operations.

(j) Concentration of Credit Risk

Financial instruments that potentially subject the Company to credit risk consist principally of trade accounts receivable, short term investments and cash. The Company believes that its credit risk is limited because the Company’s current contracts are with companies with a reliable payment history. The Company invests its excess cash in a money market fund and short term held-to maturity investment and does not believe that it is exposed to any significant risks related to its cash accounts, money market fund, or held-to maturity investments. Cash is also maintained at foreign financial institutions. Cash in foreign financial institutions as of April 30, 2023 was immaterial.

As of the year ended April 30, 2023 and 2022, the Company had two and four customers whose revenue accounted for at least 10% of the Company’s consolidated revenue, respectively. These revenues accounted for approximately 32% and 49% of the Company’s total revenue for the respective periods.

(k) Net Loss per Common Share

Basic and diluted net loss per share for all periods presented is computed by dividing net loss by the weighted average number of shares of common stock and common stock equivalents outstanding during the period. Due to the Company’s net losses, potentially dilutive securities, consisting of options to purchase shares of common stock, warrants on common stock and unvested restricted stock units issued to employees and non-employee directors, were excluded from the diluted loss per share calculation due to their anti-dilutive effect.

In computing diluted net loss per share on the Consolidated Statement of Operations, warrants on common stock, options to purchase shares of common stock and unvested restricted stock units issued to employees and non-employee directors, totaling 7,777,026 and 6,353,422 for the years ended April 30, 2023 and 2022, respectively, were excluded from each of the computations as the effect would be anti-dilutive due to the Company’s losses.

(l) Share-Based Compensation

Costs resulting from all share-based payment transactions are recognized in the consolidated financial statements at their fair values. The aggregate share-based compensation expense recorded in the Consolidated Statements of Operations for the years ended April 30, 2023 and 2022 was approximately $1.5 million and $1.2 million, respectively.

(m) Intangibles

Intangible assets acquired in a business combination are recognized separately from goodwill and are initially recognized at their fair value at the acquisition date (which is regarded as their cost). Intangible assets, including patents, are amortized over the estimated useful life of the asset on a basis that approximates the pattern of economic benefit. The patents, trade name and customer relationship intangibles are being amortized over 20, 12 and 10 years respectively, which is consistent with the estimated pattern of economic benefit of the assets. The trademark is not subject to amortization.

Intangible assets are reviewed for impairment if indicators of potential impairment exist. There was no indication of impairment of intangible assets for the fiscal years ended April 30, 2023 and April 30, 2022.

(n) Goodwill

Goodwill is assessed for impairment using a qualitative or quantitative approach. Where the Company uses a qualitative analysis it considers factors that include historical financial performance, macroeconomic and industry conditions, and the legal and regulatory environment. If the qualitative assessment indicates that it is more likely than not that an impairment exists, then a quantitative assessment is performed. The quantitative assessment requires an analysis of several estimates including future cash flows or income consistent with management’s strategic business plans, annual sales growth rates and the selection of assumptions underlying a discount rate (weighted average cost of capital) based on market data available at the time to determine fair value of the Company. If the fair value is less than the carrying amount an impairment charge for the difference is recorded. The Company acquired goodwill as part of its purchase of MAR. Management performed a qualitative assessment in fiscal year 2023 and determined that it is more likely than not that no goodwill impairment exists as of April 30, 2023.

(o) Income Taxes

Income taxes are accounted for under ACS 740 utilizing the asset and liability method. Deferred tax assets and liabilities are recognized for the future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases and operating loss and tax credit carry forwards. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences and operating loss and tax credit carry forwards are expected to be recovered, settled or utilized. In assessing the realizability of deferred tax assets, management considers whether it is more likely than not that some portion or all the deferred tax assets will not be realized. If such event occurs, a valuation allowance is recorded. The effect on deferred tax assets and liabilities of a change in tax rates is recognized in income in the period that includes the enactment date.

The Company recognizes the effect of income tax positions only if those positions are more likely than not of being sustained upon examination. Recognized income tax positions are measured at the largest amount that is greater than 50% likely of being realized. Changes in recognition or measurement are reflected in the period in which the change in judgment occurs. The Company records interest related to unrecognized tax benefits in interest expense and penalties in selling, general, and administrative expenses, to the extent incurred. Refer to Note 15 for further disclosures around our income taxes.

(p) Accumulated Other Comprehensive Loss

The functional currency for the Company’s foreign operations is the applicable local currency. The translation from the applicable foreign currencies to U.S. dollars is performed for balance sheet accounts using the exchange rates in effect at the balance sheet date and for revenue and expense accounts using an average exchange rate during the period. The unrealized gains or losses resulting from such translation are included in Accumulated Other Comprehensive Loss within Shareholders’ Equity.

(q) Warranty

The Company does not include a right of return on its products other than rights related to standard warranty provisions that permit repair or replacement of defective goods.

(r) Research and Development

Costs related to research and development activities by the Company are expensed as incurred.

(s) Recently Issued Accounting Standards

In June 2016, the Financial Accounting Standards Board (“FASB”) issued ASU No. 2016-13, “Financial Instruments - Credit Losses (Topic 326), Measurement of Credit Losses on Financial Instruments.” This amendment replaces the incurred loss impairment methodology in current GAAP with a methodology that reflects expected credit losses on instruments within its scope, including trade receivables. This update is intended to provide financial statement users with more decision-useful information about the expected credit losses. In November 2019, the FASB issued No. 2019-10, Financial Instruments—Credit Losses (Topic 326), Derivatives and Hedging (Topic 815), and Leases (Topic 842), which deferred the effective date of ASU 2016-13 for Smaller Reporting Companies for fiscal years beginning after December 15, 2022, including interim periods within those fiscal years. The Company is currently evaluating the impact the adoption of ASU 2016-13 will have on its consolidated financial statements.

Schedule of Future Minimum Lease payments Under Operating Lease (Details) $ in Thousands	Apr. 30, 2023 USD ($)
Leases
2024	$ 701
2025	494
2026	318
2027	325
Thereafter	362
Total future minimum lease payments	2,200
Less imputed interest	(360)
Total	$ 1,840

Intangible Assets

12 Months Ended

Apr. 30, 2023

Goodwill and Intangible Assets Disclosure [Abstract]

Intangible Assets

(7) Intangible Assets

The components of intangible assets, net as of April 30, 2023 and 2022 consisted of the following:

	April 30, 2023			April 30, 2022
	(in thousands)
Patents	$	2,729		$	2,729
Trademarks	$	2,769		$	2,769
Tradename	$	130		$	130
Customer Relationships	$	150		$	150
Intangible assets, gross	$	5,778		$	5,778
Accumulated amortization	$	(1,800	)	$	(1,642	)
Intangible assets, net	$	3,978		$	4,136

Amortization expense was approximately $158,000 and $86,000 for the years ended April 30, 2023 and 2022, respectively. Trademarks are not subject to amortization.

Schedule of Right-of use Assets and Lease Liabilities (Details) - USD ($) $ in Thousands	Apr. 30, 2023	Apr. 30, 2022
Leases
Operating right-of-use assets, net	$ 1,751	$ 752
Right-of-use liabilities- current	529	319
Right-of-use liabilities- long term	1,311	$ 538
Total lease liabilities	$ 1,840
Weighted average remaining lease term- operating leases	4 years 1 month 20 days
Weighted average discount rate- operating leases	8.50%

Schedule of Non-vested Restricted Stock Activity (Details) - Non-vested Restricted Stock [Member]	12 Months Ended
	Apr. 30, 2023 $ / shares shares
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Number of Shares, Unvested, Beginning \| shares	827,764
Weighted Average Price per Share, Unvested, Beginning \| $ / shares	$ 1.41
Number of Shares, Unvested, Granted \| shares	1,608,681
Weighted Average Price per Share, Unvested, Granted \| $ / shares	$ 0.75
Number of Shares, Unvested, Vested and issued \| shares	(399,429)
Weighted Average Price per Share, Unvested, Vested \| $ / shares	$ 1.38
Number of Shares, Cancelled/forfeited \| shares	(51,022)
Weighted Average Price per Share, Cancelled/forfeited \| $ / shares	$ 1.32
Number of Shares, Unvested, Ending \| shares	1,985,994
Weighted Average Price per Share, Unvested, Ending \| $ / shares	$ 0.89

Schedule of Stock Option Activity (Details)	12 Months Ended
Schedule of Stock Option Activity (Details)	Apr. 30, 2023 $ / shares shares
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Shares Underlying Options Outstanding, beginning \| shares	1,110,356
Weighted Average Exercise Price, Beginning balance \| $ / shares	$ 2.34
Weighted Average Remaining Contractual Term (In Years), Beginning	9 years 2 months 12 days
Shares underlying Options Outstanding, Granted \| shares	601,089
Weighted Average Exercise Price, Granted \| $ / shares	$ 0.68
Shares Underlying Options ,Exercised \| shares
Weighted Average Exercise Price, Exercised \| $ / shares
Shares Underlying Options, Cancelled/forfeited \| shares	(182,165)
Weighted Average Exercise Price, Cancelled/forfeited \| $ / shares	$ 1.59
Shares underlying options outstanding, expired \| shares	(95)
Weighted average exercise price, expired \| $ / shares	$ 511.12
Shares Underlying Options, ending \| shares	1,529,185
Weighted average exercise price, ending balance \| $ / shares	$ 1.75
Weighted Average Remaining Contractual Term (In Years), Ending	8 years 9 months 18 days
Shares Underlying Options, Exercisable at Ending \| shares	513,077
Weighted Average Exercise Price, Exercisable at ending \| $ / shares	$ 3.22
Weighted Average Remaining Contractual Term (In Years), Exercisable at Ending	7 years 8 months 12 days
Performance Stock Options [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Shares Underlying Options Outstanding, beginning \| shares	210,122
Weighted Average Exercise Price, Beginning balance \| $ / shares	$ 2.20
Weighted Average Remaining Contractual Term (In Years), Beginning	8 years 9 months 18 days
Shares underlying Options Outstanding, Granted \| shares
Weighted Average Exercise Price, Granted \| $ / shares
Shares Underlying Options ,Exercised \| shares
Weighted Average Exercise Price, Exercised \| $ / shares
Shares Underlying Options, Cancelled/forfeited \| shares	(143,455)
Weighted Average Exercise Price, Cancelled/forfeited \| $ / shares	$ 2.93
Shares Underlying Options, ending \| shares	66,667
Weighted average exercise price, ending balance \| $ / shares	$ 0.62
Weighted Average Remaining Contractual Term (In Years), Ending	8 years 1 month 6 days
Shares Underlying Options, Exercisable at Ending \| shares
Weighted Average Exercise Price, Exercisable at ending \| $ / shares

Employee Benefits (Details Narrative) - USD ($) $ in Millions	12 Months Ended
	Apr. 30, 2023	Apr. 30, 2022
Defined Benefit Plan Disclosure [Line Items]
Contribution percentage	100.00%
Contribution percentage	3.00%
Employee contribution percentage	6.00%
Employee Benefits and Share-Based Compensation	$ 1.5	$ 1.2
Retirement Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Employee Benefits and Share-Based Compensation	$ 0.3	$ 0.1
Minimum [Member]
Defined Benefit Plan Disclosure [Line Items]
Contribution percentage	1.00%
Maximum [Member]
Defined Benefit Plan Disclosure [Line Items]
Contribution percentage	9.00%

Share-Based Compensation Plans (Details Narrative) - USD ($)	12 Months Ended
	Apr. 30, 2023	Apr. 30, 2022	Feb. 09, 2022	Feb. 08, 2022	Jan. 18, 2018	Dec. 31, 2015
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Shares underlying options outstanding, granted	601,089
Total unrecognized compensation	$ 700,000
Share-based compensation of weighted-average period	2 years 3 months 18 days
Share-Based Payment Arrangement, Option [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Shares underlying options outstanding, granted	601,089	793,850
Intrinsic value	$ 0
Options unvested	513,000
Weighted average remaining contractual term	7 years 8 months 12 days
Share-based payment arrangement, expense	$ 300,000	$ 300,000
Employee Stock Option One [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Intrinsic value	0
Performance Shares [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Intrinsic value	$ 0
Options unvested	66,667
Weighted average remaining contractual term	8 years 1 month 6 days
Share-based payment arrangement, expense	$ 100,000	100,000
Total unrecognized compensation	$ 4,000
Share-based compensation of weighted-average period	1 month 6 days
Restricted Stock [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Share-based payment arrangement, expense	$ 1,100,000	$ 200,000
Share-based compensation of weighted-average period	1 year 4 months 24 days
Number of restricted shares, granted	1,608,681	827,764
Unrecognized compensation cost	$ 1,100,000
2015 Omnibus Incentive Plan [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Share-based compensation arrangement shares authorized	4,382,036					1,332,036
Share-based compensation arrangement shares aggregate increase	$ 3,050,000
Capital shares reserved for future issuance	221,446
2018 Inducement Plan [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Share-based compensation arrangement shares authorized			275,000	250,000
Capital shares reserved for future issuance					25,000
Available for grant	161,487

Leases (Tables)

12 Months Ended

Apr. 30, 2023

Leases

Schedule of Operating Lease Costs

The components of lease expense in the Consolidated Statement of Operations for the fiscal year ended April 30, 2023 and 2022 was as follows:

Schedule of Operating Lease Costs

	2023		2022
	Fiscal year ended April 30,
	2023		2022
Operating lease cost	$	382	$	368
Short-term lease cost		44		35
Total lease cost	$	426	$	403

Schedule of Right-of use Assets and Lease Liabilities

Information related to the Company’s right-of use assets and lease liabilities as of April 30, 2023 is as follows:

	April 30, 2023
	(in thousands)

Operating lease:
Operating right-of-use assets, net	$	1,751

Right-of-use liabilities- current		529
Right-of-use liabilities- long term		1,311
Total lease liabilities	$	1,840

Weighted average remaining lease term- operating leases		4.14 years
Weighted average discount rate- operating leases		8.5	%

Schedule of Future Minimum Lease payments Under Operating Lease

Total remaining lease payments under the Company’s operating leases are as follows:

	April 30, 2023
	(in thousands)

2024	$	701
2025		494
2026		318
2027		325
Thereafter		362
Total future minimum lease payments		2,200
Less imputed interest		(360	)
Total	$	1,840

Consolidated Statements of Cash Flows - USD ($)	12 Months Ended
Consolidated Statements of Cash Flows - USD ($)	Apr. 30, 2023	Apr. 30, 2022
Cash flows from operating activities:
Net loss	$ (26,326,000)	$ (18,874,000)
Adjustments to reconcile net loss to net cash used in operating activities:
Foreign exchange (gain) / loss	(1,000)	1,000
Depreciation of fixed assets	183,000	144,000
Amortization of intangibles	158,000	86,000
Amortization of right-of-use assets	296,000	285,000
Amortization of premium on investments	113,000	58,000
Change in contingent consideration liability	1,112,000	(60,000)
Gain on forgiveness of PPP loan		(890,000)
Loss on liquidation of subsidiary		157,000
Compensation expense related to equity compensation	1,461,000	1,169,000
Deferred tax liabilities		(377,000)
Changes in operating assets and liabilities, net of acquisitions:
Accounts receivable	(262,000)	(133,000)
Contract assets	234,000	(195,000)
Inventory	(602,000)	(292,000)
Other assets	(527,000)	19,000
Accounts payable	47,000	217,000
Accrued expenses	1,469,000	(1,004,000)
Litigation payable		(1,224,000)
Change in right of use lease liabilities	(311,000)	(309,000)
Contract liabilities	1,249,000	(74,000)
Net cash used in operating activities	(21,707,000)	(21,296,000)
Cash flows from investing activities:
Redemptions of short term investments	64,923,000
Purchases of short term investments	(43,442,000)	(49,442,000)
Purchases of property, plant, and equipment	(648,000)	(145,000)
Leased WAM-Vs built and capitalized	(371,000)
Payment for MAR acquisition, net of cash acquired		(4,444,000)
Net cash (used in) provided by investing activities	20,462,000	(54,031,000)
Cash flows from financing activities:
Proceeds from stock option exercises		90,000
Cash paid for tax withholding related to shares withheld	(14,000)	(3,000)
Net cash (used in)/provided by financing activities	(14,000)	87,000
Effect of exchange rate changes on cash, cash equivalents and restricted cash		(32,000)
Net decrease in cash, cash equivalents and restricted cash	(1,259,000)	(75,272,000)
Cash, cash equivalents and restricted cash, beginning of year	8,362,000	83,634,000
Cash, cash equivalents and restricted cash, end of year	7,103,000	8,362,000
Supplemental disclosure of noncash investing and financing activities:
Issuance of stock for acquisition		5,855,000
Operating right of use asset obtained in exchange for operating lease liability	1,296,000
Contingent liability - MAR		$ 1,591,000

Schedule of Inventory (Details) - USD ($) $ in Thousands	Apr. 30, 2023	Apr. 30, 2022
Inventory Disclosure [Abstract]
Raw Materials	$ 1,044	$ 198
Work in Process		244
Inventory, net	$ 1,044	$ 442

Schedule of Cash and Cash Equivalents and Restricted Cash (Details) - USD ($) $ in Thousands	Apr. 30, 2023	Apr. 30, 2022
Cash and Cash Equivalents [Line Items]
Cash and cash equivalents	$ 6,883	$ 7,885
Restricted cash- short term	65	258
Restricted cash- long term	155	219
Cash, cash equivalents, restricted cash and restricted cash equivalents	7,103	8,362
Checking And Savings Accounts [Member]
Cash and Cash Equivalents [Line Items]
Cash and cash equivalents	2,874	1,815
Money Market Funds [Member]
Cash and Cash Equivalents [Line Items]
Cash and cash equivalents	$ 4,009	$ 6,070

Warrants (Details Narrative) - $ / shares	Apr. 30, 2023	Mar. 31, 2023
Subsidiary, Sale of Stock [Line Items]
Warrants to purchase common stock exercised	732,500
Underwritten Public Offering [Member]
Subsidiary, Sale of Stock [Line Items]
Warrants to purchase common stock exercised		4,927,680
Exercise price of warrants		$ 3.85
Warrants and rights outstanding, term		5 years

Account Receivable, Contract Assets, and Contract Liabilities (Tables)

12 Months Ended

Apr. 30, 2023

Account Receivable Contract Assets And Contract Liabilities

Schedule of Accounts Receivable, Contract Assets and Contract Liabilities

The following provides further details on the balance sheet accounts of accounts receivable, contract assets and contract liabilities from contracts with customers:

	2023		2022
	Fiscal year ended April 30,
	2023		2022		2021
	(in thousands)

Accounts receivable	$	745	$	482	$	350
Contract assets		152		386		190
Contract liabilities		1,378		129		—

Schedule of Significant Changes in Contract assets

Significant changes in the contract assets balances during the period are as follows:

	2023			2022
	Fiscal year ended April 30,
	2023			2022
	(in thousands)

Transferred to receivables from contract assets recognized at the beginning of the period	$	(1,768	)	$	(190	)
Revenue recognized and not billed as of the end of the period		1,534			386
Net change in contract assets	$	(234	)	$	196

Schedule of Significant Changes in Contract Liabilities

Significant changes in the contract liabilities balances during the period are as follows:

	2023			2022
	Fiscal year ended April 30,
	2023			2022
	(in thousands)

Revenue recognized that was included in the contract liabilities balance as of the beginning of the period	$	(574	)	$	—
Contract liabilities obtained in acquisition of MAR		—			(203	)
Payments collected for which revenue has not been recognized		1,823			129
Net change in contract liabilities	$	1,249		$	(74	)

Other Current Assets (Tables)

12 Months Ended

Apr. 30, 2023

Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]

Schedule of Other Current Assets

Other current assets consist of the following at April 30, 2023 and 2022:

Schedule of Other Current Assets

	April 30, 2023		April 30, 2022
	(in thousands)
Prepaid insurance	$	358	$	182
Prepaid software & licenses		190		127
Prepaid registrations and memberships		122		—
Prepaid expenses- other		324		158
Total other current assets	$	994	$	467

Consolidated Statements of Shareholders' Equity - USD ($) $ in Thousands	Common Stock [Member]	Treasury Stock, Common [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	AOCI Attributable to Parent [Member]	Total
Balance at Apr. 30, 2021	$ 52	$ (338)	$ 315,821	$ (234,896)	$ (171)	$ 80,468
Balance, shares at Apr. 30, 2021	52,479,051	(21,040)
Net loss				(18,874)		(18,874)
Share-based compensation			1,169			1,169
Proceeds from stock options exercises	$ 1		90			91
Proceeds from stock options exercises, shares	96,000
Issuance of shares in acquisition	$ 3		5,852			5,855
Issuance of shares in acquisition, shares	3,330,162
Shares withheld for tax withholdings		$ (3)				(3)
Shares withheld for tax withholdings, shares		(2,312)
Liquidation of subsidiary					157	157
Other comprehensive gain/(loss)					(32)	(32)
Shares withheld for tax withholdings		$ 3				3
Shares withheld for tax withholdings, shares		2,312
Balance at Apr. 30, 2022	$ 56	$ (341)	322,932	(253,770)	(46)	68,831
Balance, shares at Apr. 30, 2022	55,905,213	(23,352)
Net loss				(26,326)		(26,326)
Share-based compensation			1,461			$ 1,461
Proceeds from stock options exercises, shares
Shares withheld for tax withholdings		$ 14				$ 14
Shares withheld for tax withholdings, shares		17,562
Other comprehensive gain/(loss)					1	1
Common stock issued upon vesting of restricted stock units
Common stock issued upon vesting of restricted stock, shares	399,429
Shares withheld for tax withholdings		$ (14)				(14)
Shares withheld for tax withholdings, shares		(17,562)
Balance at Apr. 30, 2023	$ 56	$ (355)	$ 324,393	$ (280,096)	$ (45)	$ 43,953
Balance, shares at Apr. 30, 2023	56,304,642	(40,914)

Other Current Assets

12 Months Ended

Apr. 30, 2023

Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]

Other Current Assets

(5) Other Current Assets

Other current assets consist of the following at April 30, 2023 and 2022:

Schedule of Other Current Assets

	April 30, 2023		April 30, 2022
	(in thousands)
Prepaid insurance	$	358	$	182
Prepaid software & licenses		190		127
Prepaid registrations and memberships		122		—
Prepaid expenses- other		324		158
Total other current assets	$	994	$	467

Summary of Significant Accounting Policies (Tables)

12 Months Ended

Apr. 30, 2023

Accounting Policies [Abstract]

Schedule of Revenue Recognizes From Operating Lease Arrangements

The below table represents the total revenue recognized under ASC 606 and ASC 842 fiscal years ended April 30, 2023 and 2022:

	Fiscal year ended April 30, 2023						Fiscal year ended April 30, 2022
	ASC 606		ASC 842		Total		ASC 606		ASC 842		Total
	(in thousands)						(in thousands)
Product Line:
WAM-V	$	919	$	667	$	1,586	$	401	$	—	$	401
Buoy		269		—		269		379		—		379
Services		877		—		877		979		—		979
Total	$	2,065	$	667	$	2,732	$	1,759	$	—	$	1,759

Region:
North and South America	$	1,812	$	667	$	2,479	$	1,633	$	—	$	1,633
Europe		—		—		—		19		—		19
Asia and Australia		253		—		253		107		—		107
Total	$	2,065	$	667	$	2,732	$	1,759	$	—	$	1,759

Schedule of Cash and Cash Equivalents and Restricted Cash

	April 30, 2023		April 30, 2022
	(in thousands)
Checking and savings accounts	$	2,874	$	1,815
Money market account		4,009		6,070
Cash and cash equivalents	$	6,883	$	7,885

Schedule of Cash and Cash Equivalents and Restricted Cash

	April 30, 2023		April 30, 2022
	(in thousands)
Cash and cash equivalents	$	6,883	$	7,885
Restricted cash- short term		65		258
Restricted cash- long term		155		219
	$	7,103	$	8,362

Schedule of Investments and Unrealized Gains/Losses

The following table summarizes the Company’s short term investments as of April 30, 2023 and 2022:

	April 30, 2023						April 30, 2022
Category	Amortized Cost		Unrealized Gains (Losses)		Market Value		Amortized Cost		Unrealized Gains (Losses)			Market Value
	(in thousands)
Corporate Bonds	$	14,776	$	100	$	14,876	$	37,777	$	995		$	38,772
Government Bonds & Notes	$	9,188	$	33	$	9,221	$	9,076	$	(1,022	)	$	8,054
Government Agency	$	3,826	$	25	$	3,851	$	2,531	$	(11	)	$	2,520
Total Short Term Investments	$	27,790	$	158	$	27,948	$	49,384	$	(38	)	$	49,346

Schedule of Property, Plant and Equipment, Useful Life

Description		Estimated useful life

Equipment		5-7 years
Computer equipment & software		3 years
Office furniture & fixtures		3-7 years
Leasehold improvements		Shorter of the estimated useful life or lease term
Leased WAM-V assets		10 years

Commitments and Contingencies (Details Narrative) - Tax Authority, Spain [Member]	Jan. 25, 2021 EUR (€)	Apr. 30, 2022 USD ($)	Apr. 30, 2022 EUR (€)
Operating Loss Carryforwards [Line Items]
Income tax penalties		$ 331,000	€ 279,870
Payment of tax on damages	€ 279,870

Schedule of Accounts Receivable, Contract Assets and Contract Liabilities (Details) - USD ($) $ in Thousands	Apr. 30, 2023	Apr. 30, 2022	Apr. 30, 2021
Account Receivable Contract Assets And Contract Liabilities
Accounts receivable	$ 745	$ 482	$ 350
Contract assets	152	386	190
Contract liabilities	$ 1,378	$ 129

Schedule of Operating Lease Costs (Details) - USD ($) $ in Thousands	12 Months Ended
	Apr. 30, 2023	Apr. 30, 2022
Leases
Operating lease cost	$ 382	$ 368
Short-term lease cost	44	35
Total lease cost	$ 426	$ 403

Goodwill

12 Months Ended

Apr. 30, 2023

Goodwill and Intangible Assets Disclosure [Abstract]

Goodwill

(8) Goodwill

Goodwill in the amount of $8.5 million was recognized in November 2021 related to the acquisition of MAR. There have been no additions to or impairment of goodwill during the years ended April 30, 2023 and 2022.

Intangible Assets (Details Narrative) - USD ($)	12 Months Ended
Intangible Assets (Details Narrative) - USD ($)	Apr. 30, 2023	Apr. 30, 2022
Goodwill and Intangible Assets Disclosure [Abstract]
Amortization expense	$ 158,000	$ 86,000

Income Taxes

12 Months Ended

Apr. 30, 2023

Income Tax Disclosure [Abstract]

Income Taxes

(15) Income Taxes

Loss before income taxes for the years ended April 30, 2023 and 2022 consisted of the following components:

	April 30, 2023			April 30, 2022
	(in thousands)
Domestic	$	(26,578	)	$	(20,665	)
Foreign		(26	)		(32	)
Total loss before income taxes	$	(26,604	)	$	(20,697	)

Tax Rate Reconciliation

The effective income tax rate differed from the percentages computed by applying the U.S. federal income tax rate for the periods ended April 30, 2023 and 2022 to loss before income taxes as a result of the following:

	April 30, 2023			April 30, 2022
Computed expected tax benefit		(21.0	)%		(21.0	)%
Increase(reduction) in income taxes resulting from:
State income taxes, net of federal benefit		4.0	%		5.2	%
Federal research and development tax credits		1.9	%		(0.6	)%
Foreign rate differential		—	%		—	%
Other non-deductible expenses		(1.1	)%		(0.9	)%
Proceeds of sale of New Jersey tax benefits		(7.0	)%		(7.0	)%
Other		1.3	%		1.3	%
Increase in valuation allowance		22.9	%		14.1	%
Income tax (benefit)		1.0	%		(8.9	)%

Significant Components of Deferred Taxes

The tax effects of temporary differences and carry forwards that give rise to the Company’s deferred tax assets and deferred tax liabilities are presented below.

	April 30, 2023			April 30, 2022
	(in thousands)
Deferred tax assets:
Federal net operating loss carryforwards	$	43,788		$	40,338
Foreign net operating loss carryforwards		2,059			2,061
State operating loss carryforwards		1,578			968
Federal and New Jersey research and development tax credits		5,143			4,167
Stock compensation		662			429
Accrued expenses		474			79
Capitalized section 174 research & development		1,453			-
Leases		448			207
Other		76			142
Net deferred tax assets before valuation allowance	$	55,681		$	48,391
Valuation allowance	$	(54,644	)		(47,597	)
Deferred tax assets	$	1,037		$	794

Deferred tax liabilities:
Lease liabilities	$	448		$	203
Intangibles		792			794
Net deferred tax liabilities	$	(203	)	$	(203	)

In assessing the realizability of deferred tax assets, management considers whether it is more likely than not that some portion or all the deferred tax assets will not be realized. The ultimate realization of deferred tax assets is dependent upon the generation of future taxable income during the periods in which those temporary differences and carry forwards become deductible or are utilized. As of April 30, 2023 and 2022, based upon the level of historical taxable losses, valuation allowances of $54.6 million and $47.6 million, respectively, were recorded to fully offset deferred tax assets. The valuation allowance increased $7 million during the year ended April 30, 2023 and increased $2.5 million during the year ended 2022 respectively, due to continuing net operating losses.

As of April 30, 2023, the Company had net operating loss carry forwards for federal income tax purposes of approximately $207.8 million, which begin to expire in fiscal 2023; $72.8 million of the federal carryforward has no expiration, but the deductibility of such federal net operating losses may be limited to 80% of our taxable income in future years. The Company also had federal research and development tax credit carry forwards of approximately $4.0 million as of April 30, 2023, which begins to expire in 2024. The Tax Reform Act of 1986 contains provisions that limit the utilization of net operating loss and tax credit carry forwards if there has been an ownership change, as defined. The Company has determined that as a result of multiple ownership changes, as described in Section 382 of the Internal Revenue Code, its ability to utilize these NOL’s and research and development tax credit have been significantly limited.

In addition, as of April 30, 2023, the Company had state net operating loss carry forwards of approximately $22.5 million which begin to expire in 2042, which also may be limited to utilization limitations. Further, as of April 30, 2023, the Company had foreign net operating loss carry forwards of approximately $10.8 million. The ability to utilize these carry forwards may also be limited due to ownership changes.

Income Tax Benefit

The Company has sold New Jersey State net operating losses and research development credits under the New Jersey Economic Development Authority Tax Transfer programs, The income tax benefit for the years ended April 30, 2023 and 2022 consisted of state minimum tax benefits of $0.3 million and $1.4 million, respectively, from the sale of New Jersey net operating losses and research and development credits. New Jersey-based technology or biotechnology companies with fewer than 225 US employees may be eligible to sell net operating losses and research and development tax credits to unaffiliated corporations, up to a maximum lifetime benefit of $20 million per business.

Uncertain Tax Positions

The Company applies the guidance issued by the FASB for the accounting and reporting of uncertain tax positions. The guidance requires the Company to recognize in its consolidated financial statements the impact of a tax position if that position is more likely than not to be sustained upon examination, based on the technical merits of the position. The Company is currently undergoing an income tax audit in Spain for the period from 2011 to 2014, when the Company’s Spanish branch was closed. At April 30, 2023 and 2022, the Company had no other unrecognized tax positions. The Company does not expect any material increase or decrease in its income tax expense in the next fiscal year, related to examinations or uncertain tax positions. Net operating loss and credit carry forwards since inception remain open to examination by taxing authorities and will continue to remain open for a period after utilization.

The Company does not have any interest or penalties accrued related to uncertain tax positions as it does not have any unrecognized tax benefits.

Tax Law Update

Effective for tax years beginning after December 31, 2021, taxpayers are required to capitalize any expenses incurred that are considered incidental to research and experimentation (“R&E”) activities under IRC Section 174. While taxpayers historically had the option of deducting these expenses under IRC Section 174, the December 2017 Tax Cuts and Jobs Act mandates capitalization and amortization of R&E expenses for tax years beginning after December 31, 2021. Expenses incurred in connection with R&E activities in the US must be amortized over a 5-year period if incurred, and R&E expenses incurred outside the US must be amortized over a 15-year period. R&E activities are broader in scope than qualified research activities that are considered under IRC Section 41 (relating to the research tax credit). The Company prepared an analysis if the tax impact of capitalizing and amortizing these costs over the required periods and for calendar year 2022, it is expected to be in a loss position after the estimated add back.

- Definition

The entire disclosure for income taxes. Disclosures may include net deferred tax liability or asset recognized in an enterprise's statement of financial position, net change during the year in the total valuation allowance, approximate tax effect of each type of temporary difference and carryforward that gives rise to a significant portion of deferred tax liabilities and deferred tax assets, utilization of a tax carryback, and tax uncertainties information.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480990/946-20-50-13

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 235
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(h)(2))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480678/235-10-S99-1

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-Name Accounting Standards Codification
-Publisher FASB
-URI https://asc.fasb.org//740/tableOfContent

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 14
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482685/740-10-50-14

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 21
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482685/740-10-50-21

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 270
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482526/740-270-50-1

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 17
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482685/740-10-50-17

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-Paragraph 1
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+ Details

Schedule of Stock Option Valuation Assumptions (Details) - Share-Based Payment Arrangement, Option [Member]	12 Months Ended
	Apr. 30, 2023	Apr. 30, 2022
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Risk-free interest rate	3.50%	1.50%
Expected dividend yield	0.00%	0.00%
Expected life (in years)	5 years 6 months	5 years 6 months
Expected volatility	109.00%	121.90%

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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Reference 4: http://www.xbrl.org/2003/role/disclosureRef
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+ Details

Schedule of Significant Changes in Contract Liabilities (Details) - USD ($) $ in Thousands	12 Months Ended
	Apr. 30, 2023	Apr. 30, 2022
Account Receivable Contract Assets And Contract Liabilities
Revenue recognized that was included in the contract liabilities balance as of the beginning of the period	$ (574)
Contract liabilities obtained in acquisition of MAR		(203)
Payments collected for which revenue has not been recognized	1,823	129
Net change in contract liabilities	$ 1,249	$ (74)

Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Apr. 30, 2023	Apr. 30, 2022
Income Statement [Abstract]
Revenues	$ 2,732	$ 1,759
Cost of revenues	2,496	1,860
Gross profit (loss)	236	(101)
(Gain)/loss from change in fair value of consideration	1,112	(60)
Operating expenses	28,340	21,512
Total operating expenses	29,452	21,452
Operating loss	(29,216)	(21,553)
Interest income, net	902	124
Other income, employee retention credit	1,251
Other income, proceeds from insurance claim	458
Gain on extinguishment of PPP loan		890
Loss on liquidation of subsidiary		(157)
Foreign exchange (loss) / gain	1	(1)
Loss before income taxes	(26,604)	(20,697)
Income tax benefit	278	1,823
Net loss	$ (26,326)	$ (18,874)
Earnings per share, basic	$ (0.47)	$ (0.35)
Earnings per share, diluted	$ (0.47)	$ (0.35)
Weighted average number of shares outstanding, basic	55,998,543	54,010,233
Weighted average number of shares outstanding, diluted	55,998,543	54,010,233

Income Taxes (Details Narrative) - USD ($) $ in Thousands	12 Months Ended
Income Taxes (Details Narrative) - USD ($) $ in Thousands	Apr. 30, 2023	Apr. 30, 2022
Operating Loss Carryforwards [Line Items]
Deferred Tax Assets, Valuation Allowance	$ 54,644	$ 47,597
Valuation Allowance, Deferred Tax Asset, Increase (Decrease), Amount	7,000	2,500
Net operating loss carry forwards	$ 207,800
Operating loss carryforwards, expiration description	begin to expire in fiscal 2023
Operating loss carryforwards subject to no expiration	$ 72,800
Operating loss carryforwards, expiration description	the deductibility of such federal net operating losses may be limited to 80% of our taxable income in future years.
Income tax benefit	$ (278)	(1,823)
Description of tax credit carryforward, limitations on use	Expenses incurred in connection with R&E activities in the US must be amortized over a 5-year period if incurred, and R&E expenses incurred outside the US must be amortized over a 15-year period.
Maximum [Member]
Operating Loss Carryforwards [Line Items]
Income tax benefit, net operating losses	$ 20,000
Income tax benefit, research and development expense	20,000
New Jersey Division of Taxation [Member]
Operating Loss Carryforwards [Line Items]
Income tax benefit	300	$ 1,400
State and Local Jurisdiction [Member]
Operating Loss Carryforwards [Line Items]
Net operating loss carry forwards	$ 22,500
Operating loss carryforwards, expiration description	begin to expire in 2042, which also may be limited to utilization limitations.
Foreign Tax Authority [Member]
Operating Loss Carryforwards [Line Items]
Net operating loss carry forwards	$ 10,800
Research and Development Expense [Member]
Operating Loss Carryforwards [Line Items]
Tax Credit Carryforward, Amount	$ 4,000

Background and Liquidity

12 Months Ended

Apr. 30, 2023

Accounting Policies [Abstract]

Background and Liquidity

(1) Background and Liquidity

(a) Background

Ocean Power Technologies, Inc. (the “Company”) was founded in 1984 in New Jersey, commenced business operations in 1994 and re-incorporated in Delaware in 2007. We provide ocean data collection and reporting, marine power, offshore communications and Domain Awareness Systems (“MDA” or “MDAS”) products, integrated solutions, and consulting services. Our solutions focus on four major service areas: Data as a Service (“DaaS”), which includes data collected by our Wave Adaptive Modular Vessel (WAM-V®) autonomous vehicles or our PowerBuoy® product lines; Robotics as a Service (“RaaS”), which provides a lower cost subscription model for our customers to access use of our WAM-V’s®; Power as a Service (“PaaS”), which includes our PowerBuoy® and subsea battery products; and our Strategic Consulting Services. We offer our products and services to a wide-range of customers, including those in government and offshore energy, oil and gas, construction, wind power and other industries. We are involved in the entire life cycle of product development, from product design through manufacturing, testing, deployment, maintenance and upgrades, while working closely with partners across our supply chain. Our solutions are based on technologies that enable autonomous, zero or low carbon emitting, and cost effective data collection, analysis, transportation and communication. Our solutions are primarily suited to ocean and other offshore environments, and support generation of actionable intelligence on a standalone basis or working with other data sources. We then channel the information we collect, and other communications, through control equipment linked to edge computing and cloud hosting environments. Our goal is to generate most of our revenues from the sale or lease of our products and solutions, and sales of services to support our business operations. As we continue to develop and commercialize our products and services, we expect to have a net decrease in cash due to the use of cash from operating activities unless and until we achieve positive cash flow from the commercialization of products, solutions and services.

(b) Liquidity

For the fiscal year ended April 30, 2023, and the fiscal year ended April 30, 2022, the Company incurred net losses of approximately $26.3 million and $18.9 million, respectively, and used cash in operating activities of approximately $21.7 million and $21.3 million, respectively. The Company has continued to make investments in ongoing product development efforts and in building inventory in anticipation of, and in support of, future growth. The Company’s future results of operations involve significant risks and uncertainties. Factors that could affect the Company’s future operating results and could cause actual results to vary materially from expectations include, but are not limited to, performance of its products, its ability to market and commercialize its products and new products that it may develop, technology development, scalability of technology and production, ability to attract and retain key personnel, concentration of customers and suppliers, pending or threatened litigation, and deployment risks and integration of acquisitions. For fiscal year 2023 to date and through the date of filing of this form 10-K, management has not obtained any additional capital financing. Management believes the Company’s current cash balance of $6.9 million and short term investments balance of $27.8 million is sufficient to fund its planned operations through at least July 31, 2024.

Share-Based Compensation Plans (Tables)

12 Months Ended

Apr. 30, 2023

Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]

Schedule of Stock Option Valuation Assumptions

	Fiscal year ended April 30,
	2023			2022
Risk-free interest rate		3.5	%		1.5	%
Expected dividend yield		0.0	%		0.0	%
Expected life (in years)		5.5			5.5
Expected volatility		109.0	%		121.9	%

Schedule of Stock Option Activity

A summary of stock options under our Stock Incentive Plans is detailed in the following table.

Schedule of Stock Option Activity

	Shares Underlying Options			Weighted Average Exercise Price		Weighted Average Remaining Contractual Term (In Years)
Outstanding as of April 30, 2022		1,110,356		$	2.34		9.2
Granted		601,089		$	0.68
Exercised		—		$	—
Cancelled/forfeited		(182,165	)	$	1.59
Expired		(95	)	$	511.12
Outstanding as of April 30, 2023		1,529,185		$	1.75		8.8
Exercisable as of April 30, 2023		513,077		$	3.22		7.7

Schedule of Non-vested Restricted Stock Activity

A summary of unvested restricted stock units under our stock incentive plans is as follows:

	Number of Shares			Weighted Average Price per Share
Issued and unvested at April 30, 2022		827,764		$	1.41
Granted		1,608,681		$	0.75
Vested and issued		(399,429	)	$	1.38
Cancelled/forfeited		(51,022	)	$	1.32
Issued and unvested at April 30, 2023		1,985,994		$	0.89

Performance Stock Options [Member]

Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]

Schedule of Stock Option Activity

A summary of performance stock options under our stock incentive plans is detailed in the following table.

Schedule of Stock Option Activity

	Shares Underlying Options			Weighted Average Exercise Price		Weighted Average Remaining Contractual Term (In Years)
Outstanding as of April 30, 2022		210,122		$	2.20		8.8
Granted		—		$	—
Exercised		—		$	—
Cancelled/forfeited		(143,455	)	$	2.93
Outstanding as of April 30, 2023		66,667		$	0.62		8.1
Exercisable as of April 30, 2023		—		$	—

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

+ Details

Account Receivable, Contract Assets, and Contract Liabilities

12 Months Ended

Apr. 30, 2023

Account Receivable Contract Assets And Contract Liabilities

Account Receivable, Contract Assets, and Contract Liabilities

(3) Account Receivable, Contract Assets, and Contract Liabilities

The following provides further details on the balance sheet accounts of accounts receivable, contract assets, and contract liabilities.

Accounts Receivable

The following provides further details on the balance sheet accounts of accounts receivable, contract assets and contract liabilities from contracts with customers:

	2023		2022
	Fiscal year ended April 30,
	2023		2022		2021
	(in thousands)

Accounts receivable	$	745	$	482	$	350
Contract assets		152		386		190
Contract liabilities		1,378		129		—

Contract Assets

Significant changes in the contract assets balances during the period are as follows:

	2023			2022
	Fiscal year ended April 30,
	2023			2022
	(in thousands)

Transferred to receivables from contract assets recognized at the beginning of the period	$	(1,768	)	$	(190	)
Revenue recognized and not billed as of the end of the period		1,534			386
Net change in contract assets	$	(234	)	$	196

Contract assets include unbilled amounts typically resulting from arrangements whereby the right to payment is conditioned on completing additional tasks or services for a performance obligation. The decrease in contract assets is primarily a result of services performed that were billed during the fiscal year ended April 30, 2023.

Contract Liabilities

Significant changes in the contract liabilities balances during the period are as follows:

	2023			2022
	Fiscal year ended April 30,
	2023			2022
	(in thousands)

Revenue recognized that was included in the contract liabilities balance as of the beginning of the period	$	(574	)	$	—
Contract liabilities obtained in acquisition of MAR		—			(203	)
Payments collected for which revenue has not been recognized		1,823			129
Net change in contract liabilities	$	1,249		$	(74	)

Contract liabilities consist of amounts invoiced to customers in excess of revenue recognized. The increase in contract liabilities is primarily due to payment for government projects received during the fiscal year ended April 30, 2023 for which we have not recognized revenue.

Subsequent Events

12 Months Ended

Apr. 30, 2023

Subsequent Events [Abstract]

Subsequent Events

(19) Subsequent Events

Earn out payment

On November 15, 2021, the Company entered into a stock purchase agreement with the sellers named therein (the “Sellers”) pursuant to which the Company acquired from the Sellers all the outstanding equity interest of Marine Advanced Robotics, Inc. (“MAR”). MAR is a Richmond, California based company that is the developer of Wave Adaptive Modular Vessel technology, which enables roaming capabilities for unmanned equipment in waters around the world. In consideration for the purchase, the Company paid $4,000,000 in cash to the Sellers and issued 3,330,162 shares of our common stock to the Sellers. Pursuant to registration rights that we granted under such stock purchase agreement, the Company previously filed a registration statement to register the resale of the 3,330,162 shares of our common stock that we issued to the Sellers.

On June 29, 2023, the Company issued an additional 2,403,846 shares of our common stock to the Sellers and to certain employees of MAR. 1,923,077 shares related to the earnout provisions of such stock purchase agreement, as well as 480,769 shares related to performance bonuses for MAR employees which was not related to the business combination, and further agreed to register the resale of such additional shares. The Company filed a registration statement on Form S-3 on June 30, 2023 to this effect.

Tax benefits preservation plan

On June 30, 2023, the Company adopted a tax benefits preservation plan in the form of a Section 382 Rights Agreement. Under the terms of this plan, if enacted by the Company’s Board of Directors, each common shareholder is entitled to one preferred stock purchase right for each share of OPT’s common stock held as of the close of business on July 11, 2023 (the record date). Management assessed the impact of the distribution of the rights and deemed the issuance of the rights to existing shareholders to be a freestanding equity instrument.

Goodwill (Details Narrative) - USD ($) $ in Thousands	Apr. 30, 2023	Apr. 30, 2022	Nov. 30, 2021
Goodwill	$ 8,537	$ 8,537
Marine Advanced Robotics, Inc. [Member]
Goodwill			$ 8,500

- Definition

Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

+ References + Details

Accrued Expenses

12 Months Ended

Apr. 30, 2023

Payables and Accruals [Abstract]

Accrued Expenses

(10) Accrued Expenses

Accrued expenses consisted of the following at April 30, 2023 and 2022:

Schedule of Accrued Expenses

	April 30, 2023		April 30, 2022
	(in thousands)
Project costs	$	181	$	59
Contract loss reserve		—		328
Employee incentive payments		1,948		266
Accrued salary and benefits		52		60
Professional Fees		—		30
Other		165		134
Accrued expenses total	$	2,346	$	877

Property and Equipment

12 Months Ended

Apr. 30, 2023

Property, Plant and Equipment [Abstract]

Property and Equipment

(6) Property and Equipment

The components of property and equipment as of April 30, 2023 and 2022 consisted of the following:

	April 30, 2023			April 30, 2022
	(in thousands)
Equipment	$	783		$	615
Computer equipment & software		700			571
Office furniture & equipment		386			352
Leasehold improvements		611			477
Leased WAM-V’s		371			—
Construction in process		—			15
Property and equipment, gross	$	2,851		$	2,030
Less: accumulated depreciation		(1,571	)		(1,585	)
Property and equipment, net	$	1,280		$	445

Leased WAM-V’s represent fixed assets that are part of underlying operating leases with customers as discussed in revenue recognition section related to ASC 842.

Depreciation expense was approximately $183,000 and $144,000 for years ended April 30, 2023 and 2022, respectively.

Consolidated Balance Sheets (Parenthetical) - $ / shares	Apr. 30, 2023	Apr. 30, 2022
Statement of Financial Position [Abstract]
Preferred stock, par value	$ 0.001	$ 0.001
Preferred stock, shares authorized	5,000,000	5,000,000
Preferred stock, shares outstanding	0	0
Preferred stock, shares issued	0	0
Common stock, par value	$ 0.001	$ 0.001
Common stock, shares authorized	100,000,000	100,000,000
Common stock, shares issued	56,304,642	55,905,213
Common stock, shares outstanding	56,263,728	55,881,861
Treasury stock, shares	40,914	23,352

Commitments and Contingencies

12 Months Ended

Apr. 30, 2023

Commitments and Contingencies Disclosure [Abstract]

Commitments and Contingencies

(16) Commitments and Contingencies

Spain Income Tax Audit

The Company underwent an income tax audit in Spain for the period from 2011 to 2014, when its Spanish branch was closed. On July 30, 2018, the Spanish tax inspector concluded that although there was no tax owed in light of losses reported, the Company’s Spanish branch owed penalties for failure to properly account for the income associated with the funding grant. During the year ended April 30, 2022, the Company received notice from the Spanish Central Economic and Administrative Tribunal (“Spanish Tax Administration”) that it agreed with the inspector and ruled that the Company owes the full amount of the penalty in the amount of €279,870 or approximately $331,000. On January 25, 2021,the Company paid the Spanish Tax Administration €279,870. Notwithstanding that payment, on April 30, 2022, the Company filed its appeal of the decision of the Central Court to the Spanish National Court.

General Legal Matters

From time to time, the Company is involved in legal and administrative proceedings and claims of various types. The Company records a liability in its consolidated financial statements for these matters when a loss is known or considered probable, and the amount can be reasonably estimated. The Company reviews these estimates each accounting period as additional information is known and adjusts the loss provision when appropriate. If a matter is both probable to result in a liability and the amounts of loss can be reasonably estimated, the Company estimates and discloses the possible loss or range of loss to the extent necessary to make the consolidated financial statements not misleading. If the loss is not probable or cannot be reasonably estimated, a liability is not recorded in its consolidated financial statements.

Schedule of Revenue from External Customers and Long-Lived Assets, by Geographical Areas (Details) - USD ($) $ in Thousands	12 Months Ended
	Apr. 30, 2023	Apr. 30, 2022
Revenues from External Customers and Long-Lived Assets [Line Items]
Net loss	$ (26,326)	$ (18,874)
Right of use assets	1,751	752
Total assets	53,374	73,393
Operating Segment [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues from external customers	2,732	1,759
Net loss	(26,326)	(18,874)
Right of use assets	1,751
Long-lived assets	1,280	445
Total assets	53,374	73,393
North America [Member] \| Operating Segment [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues from external customers	2,479	1,633
Net loss	(26,375)	(18,732)
Right of use assets	1,751
Long-lived assets	1,280	445
Total assets	53,374	73,359
Europe [Member] \| Operating Segment [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues from external customers		19
Net loss		(11)
Right of use assets
Long-lived assets
Total assets		19
Asia and Australia [Member] \| Operating Segment [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues from external customers	253	107
Net loss	49	(131)
Right of use assets
Long-lived assets
Total assets		$ 15

Schedule of Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Apr. 30, 2023	Apr. 30, 2022
Income Tax Disclosure [Abstract]
Federal net operating loss carryforwards	$ 43,788	$ 40,338
Foreign net operating loss carryforwards	2,059	2,061
State operating loss carryforwards	1,578	968
Federal and New Jersey research and development tax credits	5,143	4,167
Stock compensation	662	429
Accrued expenses	474	79
Capitalized section 174 research & development	1,453
Leases	448	207
Other	76	142
Net deferred tax assets before valuation allowance	55,681	48,391
Valuation allowance	(54,644)	(47,597)
Deferred tax assets	1,037	794
Lease liabilities	448	203
Intangibles	792	794
Net deferred tax liabilities	$ (203)	$ (203)

Schedule of Revenue Recognizes From Operating Lease Arrangements (Details) - USD ($) $ in Thousands	12 Months Ended
	Apr. 30, 2023	Apr. 30, 2022
Product Information [Line Items]
Revenue	$ 2,732	$ 1,759
North And South America [Member]
Product Information [Line Items]
Revenue	2,479	1,633
Europe [Member]
Product Information [Line Items]
Revenue		19
Asia and Australia [Member]
Product Information [Line Items]
Revenue	253	107
Region [Member]
Product Information [Line Items]
Revenue	2,732	1,759
WAMV [Member]
Product Information [Line Items]
Revenue	1,586	401
Buoy [Member]
Product Information [Line Items]
Revenue	269	379
Service [Member]
Product Information [Line Items]
Revenue	877	979
Product [Member]
Product Information [Line Items]
Revenue	2,732	1,759
Accounting Standards Update 2014-09 [Member] \| North And South America [Member]
Product Information [Line Items]
Revenue	1,812	1,633
Accounting Standards Update 2014-09 [Member] \| Europe [Member]
Product Information [Line Items]
Revenue		19
Accounting Standards Update 2014-09 [Member] \| Asia and Australia [Member]
Product Information [Line Items]
Revenue	253	107
Accounting Standards Update 2014-09 [Member] \| Region [Member]
Product Information [Line Items]
Revenue	2,065	1,759
Accounting Standards Update 2014-09 [Member] \| WAMV [Member]
Product Information [Line Items]
Revenue	919	401
Accounting Standards Update 2014-09 [Member] \| Buoy [Member]
Product Information [Line Items]
Revenue	269	379
Accounting Standards Update 2014-09 [Member] \| Service [Member]
Product Information [Line Items]
Revenue	877	979
Accounting Standards Update 2014-09 [Member] \| Product [Member]
Product Information [Line Items]
Revenue	2,065	1,759
Accounting Standards Update 2016-02 [Member] \| North And South America [Member]
Product Information [Line Items]
Revenue	667
Accounting Standards Update 2016-02 [Member] \| Europe [Member]
Product Information [Line Items]
Revenue
Accounting Standards Update 2016-02 [Member] \| Asia and Australia [Member]
Product Information [Line Items]
Revenue
Accounting Standards Update 2016-02 [Member] \| Region [Member]
Product Information [Line Items]
Revenue	667
Accounting Standards Update 2016-02 [Member] \| WAMV [Member]
Product Information [Line Items]
Revenue	667
Accounting Standards Update 2016-02 [Member] \| Buoy [Member]
Product Information [Line Items]
Revenue
Accounting Standards Update 2016-02 [Member] \| Service [Member]
Product Information [Line Items]
Revenue
Accounting Standards Update 2016-02 [Member] \| Product [Member]
Product Information [Line Items]
Revenue	$ 667

Inventory

12 Months Ended

Apr. 30, 2023

Inventory Disclosure [Abstract]

Inventory

(4) Inventory

The Company holds inventory related to the production of our products.

Schedule of Inventory

	April 30, 2023		April 30, 2022
	(in thousands)
Raw Materials	$	1,044	$	198
Work in Process		—		244
Inventory, net	$	1,044	$	442

Paycheck Protection Program Loan

12 Months Ended

Apr. 30, 2023

Debt Disclosure [Abstract]

Paycheck Protection Program Loan

(12) Paycheck Protection Program Loan

On March 27, 2020, the U.S. Government passed into law the Coronavirus Aid, Relief and Economic Security Act, or the (“CARES Act”). On May 3, 2020, the Company signed a Paycheck Protection Program (“PPP”) loan with Santander as the lender for $890,000 in support through the Small Business Association (“SBA”) under the PPP Loan. The PPP Loan was unsecured and evidenced by a note in favor of Santander and governed by a Loan Agreement with Santander. The Company received the proceeds on May 5, 2020.

The Company filed its loan forgiveness application at the end of February 2021 asking for 100% forgiveness of the loan. In June 2021, the Company was informed that its application was approved, and that the loan has now been fully forgiven. The Company recognized a gain on forgiveness of PPP loan of approximately $890,000 during the year ended April 30, 2022 as reflected on the Consolidated Statement of Operations.

The SBA may audit a borrower’s PPP loan up to six years after the loan is forgiven. The PPP loan audit after forgiveness is conducted to ensure that the borrower has used the loan funds for eligible expenses and complied with the applicable requirements of the PPP loan program.

- Definition

The entire disclosure for information about short-term and long-term debt arrangements, which includes amounts of borrowings under each line of credit, note payable, commercial paper issue, bonds indenture, debenture issue, own-share lending arrangements and any other contractual agreement to repay funds, and about the underlying arrangements, rationale for a classification as long-term, including repayment terms, interest rates, collateral provided, restrictions on use of assets and activities, whether or not in compliance with debt covenants, and other matters important to users of the financial statements, such as the effects of refinancing and noncompliance with debt covenants.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1B
-Subparagraph (h)
-Publisher FASB
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Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 235
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(c))
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-URI https://asc.fasb.org//1943274/2147480678/235-10-S99-1

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-URI https://asc.fasb.org//470/tableOfContent

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
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Reference 6: http://www.xbrl.org/2003/role/disclosureRef
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Reference 10: http://www.xbrl.org/2003/role/disclosureRef
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-Name Accounting Standards Codification
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-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481139/470-20-50-1E

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
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-URI https://asc.fasb.org//1943274/2147481139/470-20-50-1I

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
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Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
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-Name Accounting Standards Codification
-Section 50
-Paragraph 1I
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481139/470-20-50-1I

+ Details

Employee Benefits

12 Months Ended

Apr. 30, 2023

Retirement Benefits [Abstract]

Employee Benefits

(18) Employee Benefits

401(k) Savings & Retirement Plan

The Company offers a 401(k) Savings & Retirement Plan to eligible employees meeting certain age and service requirements. This plan permits participants to contribute 100% of their salary, up to the maximum allowable by the Internal Revenue Service regulations. Participants are immediately vested in their voluntary contributions plus actual earnings or less actual losses thereon. Participants are eligible to participate in the Company match after one year of service and are fully vested in the Company match after two years of service.

The Company matches employee contributions dollar for dollar up to the first 3% and fifty cents on the dollar for each 1% up to 9% for a maximum match contribution of 6%. The aggregate employer 401(k) match expense recorded in the Consolidated Statements of Operations for the years ended April 30, 2023 and 2022 was approximately $0.3 million and $0.1 million, respectively.

The Company also provides for a voluntary contribution to the plan which is approved by the Company’s Board of Directors on an annual basis. All participants immediately vest on the date of distribution.

- Definition

The entire disclosure for retirement benefits.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-SubTopic 70
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480794/715-70-50-1

Reference 2: http://www.xbrl.org/2003/role/exampleRef
-Topic 715
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Reference 3: http://www.xbrl.org/2003/role/disclosureRef
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Reference 4: http://www.xbrl.org/2003/role/disclosureRef
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Reference 5: http://www.xbrl.org/2003/role/disclosureRef
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Reference 6: http://www.xbrl.org/2003/role/disclosureRef
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Reference 7: http://www.xbrl.org/2003/role/disclosureRef
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Reference 9: http://www.xbrl.org/2003/role/disclosureRef
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Reference 10: http://www.xbrl.org/2003/role/disclosureRef
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Reference 11: http://www.xbrl.org/2003/role/disclosureRef
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Reference 12: http://www.xbrl.org/2003/role/disclosureRef
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-URI https://asc.fasb.org//1943274/2147480506/715-20-50-1

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
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Reference 14: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
-SubTopic 60
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480266/715-60-50-3

+ Details

Fair Value Measurements

12 Months Ended

Apr. 30, 2023

Fair Value Disclosures [Abstract]

Fair Value Measurements

(14) Fair Value Measurements

ASC Topic 820,”Fair Value Measurements” states that fair value is an exit price, representing the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. Assets and liabilities that are measured at fair value are reported using a three-level fair value hierarchy that prioritizes the inputs used to measure fair value. This hierarchy maximizes the use of observable input and minimizes the use of unobservable inputs. The following is a description of the three hierarchy levels.

Level 1	Unadjusted quoted prices in active markets for identical assets or liabilities that the Company has the ability to access at the measurement date.

Level 2	Inputs other than quoted prices in active markets that are observable for the asset or liability, either directly or indirectly.

Level 3	Inputs that are unobservable for the asset or liability.

Disclosure of Fair Values

The Company’s financial instruments that are not re-measured at fair value include cash, cash equivalents, restricted cash, accounts receivable, contract assets and liabilities, deposits, accounts payable, and accrued expenses. The carrying value is equal to their fair value due to the short term nature of these accounts. The Company’s contingent consideration liability represents the only asset or liability classified financial instrument that is measured at fair value on a recurring basis.

Additionally, there is a Level 3 contingent liability related to earnouts as part of the MAR acquisition in the amount of $1.2 million as of April 30, 2023. As of April 30, 2023, the fair value of this contingent liability from the time that MAR was acquired has increased by approximately $1.1 million from $1.6 million as of April 30, 2022. Subsequent to year end in June 2023, the Company paid out $500,000 in cash and issued 1,923,077 in shares to satisfy the achievement of the earnout based on new customer bookings of $1.5 million.

Transfers into or out of any hierarchy level are recognized at the end of the reporting period in which the transfers occurred. There was one transfers between any hierarchy levels during each of the fiscal year ended April 30, 2023 related to the current portion of the MAR earnout being known and payable as of year-end in the amount of $1.5 million. There was a $60,000 adjustment for 3Dent as of the year end April 30, 2022.

- Definition

The entire disclosure for the fair value of financial instruments (as defined), including financial assets and financial liabilities (collectively, as defined), and the measurements of those instruments as well as disclosures related to the fair value of non-financial assets and liabilities. Such disclosures about the financial instruments, assets, and liabilities would include: (1) the fair value of the required items together with their carrying amounts (as appropriate); (2) for items for which it is not practicable to estimate fair value, disclosure would include: (a) information pertinent to estimating fair value (including, carrying amount, effective interest rate, and maturity, and (b) the reasons why it is not practicable to estimate fair value; (3) significant concentrations of credit risk including: (a) information about the activity, region, or economic characteristics identifying a concentration, (b) the maximum amount of loss the entity is exposed to based on the gross fair value of the related item, (c) policy for requiring collateral or other security and information as to accessing such collateral or security, and (d) the nature and brief description of such collateral or security; (4) quantitative information about market risks and how such risks are managed; (5) for items measured on both a recurring and nonrecurring basis information regarding the inputs used to develop the fair value measurement; and (6) for items presented in the financial statement for which fair value measurement is elected: (a) information necessary to understand the reasons for the election, (b) discussion of the effect of fair value changes on earnings, (c) a description of [similar groups] items for which the election is made and the relation thereof to the balance sheet, the aggregate carrying value of items included in the balance sheet that are not eligible for the election; (7) all other required (as defined) and desired information.

+ References + Details

Operating Segments and Geographic Information (Tables)

12 Months Ended

Apr. 30, 2023

Segment Reporting [Abstract]

Schedule of Revenue from External Customers and Long-Lived Assets, by Geographical Areas

	Year Ended April 30, 2023
	North & South America			Europe		Asia and Australia		Total
	(in thousands)
Revenues from external customers	$	2,479		$	—	$	253	$	2,732
Operating income (loss)		(26,375	)		—		49		(26,326	)
Right-of-use assets, net		1,751			—		—		1,751
Long-lived assets		1,280			—		—		1,280
Total assets		53,374			—		—		53,374

	Year Ended April 30, 2022
	North & South America			Europe			Asia and Australia			Total
	(in thousands)
Revenues from external customers	$	1,633		$	19		$	107		$	1,759
Operating loss		(18,732	)		(11	)		(131	)		(18,874	)
Long-lived assets		445			—			—			445
Total assets		73,359			19			15			73,393

Property and Equipment (Tables)

12 Months Ended

Apr. 30, 2023

Property, Plant and Equipment [Abstract]

Schedule of Components of Property and Equipment

The components of property and equipment as of April 30, 2023 and 2022 consisted of the following:

	April 30, 2023			April 30, 2022
	(in thousands)
Equipment	$	783		$	615
Computer equipment & software		700			571
Office furniture & equipment		386			352
Leasehold improvements		611			477
Leased WAM-V’s		371			—
Construction in process		—			15
Property and equipment, gross	$	2,851		$	2,030
Less: accumulated depreciation		(1,571	)		(1,585	)
Property and equipment, net	$	1,280		$	445

Income Taxes (Tables)

12 Months Ended

Apr. 30, 2023

Income Tax Disclosure [Abstract]

Schedule of Components of Loss Before Income Taxes

Loss before income taxes for the years ended April 30, 2023 and 2022 consisted of the following components:

	April 30, 2023			April 30, 2022
	(in thousands)
Domestic	$	(26,578	)	$	(20,665	)
Foreign		(26	)		(32	)
Total loss before income taxes	$	(26,604	)	$	(20,697	)

Schedule of Effective Income Tax Rate Reconciliation

	April 30, 2023			April 30, 2022
Computed expected tax benefit		(21.0	)%		(21.0	)%
Increase(reduction) in income taxes resulting from:
State income taxes, net of federal benefit		4.0	%		5.2	%
Federal research and development tax credits		1.9	%		(0.6	)%
Foreign rate differential		—	%		—	%
Other non-deductible expenses		(1.1	)%		(0.9	)%
Proceeds of sale of New Jersey tax benefits		(7.0	)%		(7.0	)%
Other		1.3	%		1.3	%
Increase in valuation allowance		22.9	%		14.1	%
Income tax (benefit)		1.0	%		(8.9	)%

Schedule of Deferred Tax Assets and Liabilities

The tax effects of temporary differences and carry forwards that give rise to the Company’s deferred tax assets and deferred tax liabilities are presented below.

	April 30, 2023			April 30, 2022
	(in thousands)
Deferred tax assets:
Federal net operating loss carryforwards	$	43,788		$	40,338
Foreign net operating loss carryforwards		2,059			2,061
State operating loss carryforwards		1,578			968
Federal and New Jersey research and development tax credits		5,143			4,167
Stock compensation		662			429
Accrued expenses		474			79
Capitalized section 174 research & development		1,453			-
Leases		448			207
Other		76			142
Net deferred tax assets before valuation allowance	$	55,681		$	48,391
Valuation allowance	$	(54,644	)		(47,597	)
Deferred tax assets	$	1,037		$	794

Deferred tax liabilities:
Lease liabilities	$	448		$	203
Intangibles		792			794
Net deferred tax liabilities	$	(203	)	$	(203	)

Schedule of Investments and Unrealized Gains/Losses (Details) - USD ($) $ in Thousands	12 Months Ended
	Apr. 30, 2023	Apr. 30, 2022
Schedule of Investments [Line Items]
Amortized Cost	$ 27,790	$ 49,384
Unrealized Gains (Losses)	158	(38)
Market Value	27,948	49,346
Corporate Bonds [Member]
Schedule of Investments [Line Items]
Amortized Cost	14,776	37,777
Unrealized Gains (Losses)	100	995
Market Value	14,876	38,772
Government Bonds and Notes [Member]
Schedule of Investments [Line Items]
Amortized Cost	9,188	9,076
Unrealized Gains (Losses)	33	(1,022)
Market Value	9,221	8,054
Government Agency [Member]
Schedule of Investments [Line Items]
Amortized Cost	3,826	2,531
Unrealized Gains (Losses)	25	(11)
Market Value	$ 3,851	$ 2,520

- Definition

Cost of the investment.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 946
-SubTopic 210
-Name Accounting Standards Codification
-Section 55
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480493/946-210-55-1

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-URI https://asc.fasb.org//1943274/2147480032/946-320-S99-19

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+ Details

Warrants

12 Months Ended

Apr. 30, 2023

Warrants

Warrants

(11) Warrants

Equity Classified Warrants

The underwritten public offering from April 2019 included the issuance of common stock warrants to purchase up to 4,927,680 shares of common stock that have an exercise price of $3.85 per share and expire five years from the issuance date. As of April 30, 2023, common warrants to purchase 732,500 shares of the common stock had been exercised.

Schedule of Components of Loss Before Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Apr. 30, 2023	Apr. 30, 2022
Income Tax Disclosure [Abstract]
Domestic	$ (26,578)	$ (20,665)
Foreign	(26)	(32)
Loss before income taxes	$ (26,604)	$ (20,697)

- Definition

Amount of income (loss) from continuing operations, including income (loss) from equity method investments, before deduction of income tax expense (benefit), and income (loss) attributable to noncontrolling interest.

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+ Details

Schedule of Accrued Expenses (Details) - USD ($) $ in Thousands	Apr. 30, 2023	Apr. 30, 2022
Payables and Accruals [Abstract]
Project costs	$ 181	$ 59
Contract loss reserve		328
Employee incentive payments	1,948	266
Accrued salary and benefits	52	60
Professional Fees		30
Other	165	134
Accrued expenses total	$ 2,346	$ 877

Schedule of Other Current Assets (Details) - USD ($) $ in Thousands	Apr. 30, 2023	Apr. 30, 2022
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Prepaid insurance	$ 358	$ 182
Prepaid software & licenses	190	127
Prepaid registrations and memberships	122
Prepaid expenses- other	324	158
Total other current assets	$ 994	$ 467

Summary of Significant Accounting Policies (Details Narrative) - USD ($)	12 Months Ended
	Apr. 30, 2023	Apr. 30, 2022
Product Information [Line Items]
Revenue remaining performance obligation	$ 3,900,000
Revenue remaining performance obligation	$ 4,000,000.0
Revenue remaining performance obligation, percentage	97.00%
Investment securities	$ 27,790,000	$ 49,384,000
Interest expense on the premium/discount	$ 122,000	$ 58,000
Antidilutive securities excluded from computation of earnings per share, amount	7,777,026	6,353,422
Employee Benefits and Share-Based Compensation	$ 1,500,000	$ 1,200,000
Trade Names [Member]
Product Information [Line Items]
Intangible asset estimated lives	12 years
Customer Relationships [Member]
Product Information [Line Items]
Intangible asset estimated lives	10 years
Revenue Benchmark [Member] \| Customer Concentration Risk [Member] \| Two And Four Customers [Member]
Product Information [Line Items]
Concentration risk percentage	32.00%	49.00%
Transferred over Time [Member]
Product Information [Line Items]
Revenue remaining performance obligation	$ 1,000,000.0
Transferred at Point in Time [Member]
Product Information [Line Items]
Revenue remaining performance obligation	$ 1,700,000

Paycheck Protection Program Loan (Details Narrative) - Paycheck Protection Program [Member] - USD ($)			12 Months Ended
	Feb. 28, 2021	May 03, 2020	Apr. 30, 2023
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Proceeds from loan originations		$ 890,000
Debt forgiveness, description	The Company filed its loan forgiveness application at the end of February 2021 asking for 100% forgiveness of the loan. In June 2021, the Company was informed that its application was approved, and that the loan has now been fully forgiven. The Company recognized a gain on forgiveness of PPP loan of approximately $890,000 during the year ended April 30, 2022 as reflected on the Consolidated Statement of Operations.
Debt interest rate	100.00%
Repayments of long-term debt			$ 890,000

Intangible Assets (Tables)

12 Months Ended

Apr. 30, 2023

Goodwill and Intangible Assets Disclosure [Abstract]

Schedule of Components of Intangible Assets

The components of intangible assets, net as of April 30, 2023 and 2022 consisted of the following:

	April 30, 2023			April 30, 2022
	(in thousands)
Patents	$	2,729		$	2,729
Trademarks	$	2,769		$	2,769
Tradename	$	130		$	130
Customer Relationships	$	150		$	150
Intangible assets, gross	$	5,778		$	5,778
Accumulated amortization	$	(1,800	)	$	(1,642	)
Intangible assets, net	$	3,978		$	4,136

Fair Value Measurements (Details Narrative) - USD ($)		12 Months Ended
Fair Value Measurements (Details Narrative) - USD ($)	Jun. 01, 2023	Apr. 30, 2023
Subsequent Event [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Stock Issued During Period, Value, New Issues	$ 500,000
Stock Issued During Period, Shares, New Issues	1,923,077
Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Contingent liability MAR acquisition amount		$ 1,200,000
Increased in contingent liability		1,100,000
Fair value of contingent consideration		1,600,000
contingent liability related to earnouts		1,500,000
Loans payable		1,500,000
Notes Payable		$ 60,000

Operating Segments and Geographic Information

12 Months Ended

Apr. 30, 2023

Segment Reporting [Abstract]

Operating Segments and Geographic Information

(17) Operating Segments and Geographic Information

The Company’s business consists of one segment as the revenue associated with its different business lines are not material enough to justify segment reporting or to make it meaningful to investors, and our chief operating decision maker does not view the Company’s operations on a segment basis. The Company operates on a worldwide basis with one operating company in the U.S. and one operating subsidiary in the UK. Revenues and expenses are generally attributed to the operating unit that bills the customers. Geographic information is as follows:

	Year Ended April 30, 2023
	North & South America			Europe		Asia and Australia		Total
	(in thousands)
Revenues from external customers	$	2,479		$	—	$	253	$	2,732
Operating income (loss)		(26,375	)		—		49		(26,326	)
Right-of-use assets, net		1,751			—		—		1,751
Long-lived assets		1,280			—		—		1,280
Total assets		53,374			—		—		53,374

	Year Ended April 30, 2022
	North & South America			Europe			Asia and Australia			Total
	(in thousands)
Revenues from external customers	$	1,633		$	19		$	107		$	1,759
Operating loss		(18,732	)		(11	)		(131	)		(18,874	)
Long-lived assets		445			—			—			445
Total assets		73,359			19			15			73,393

- Definition

The entire disclosure for reporting segments including data and tables. Reportable segments include those that meet any of the following quantitative thresholds a) it's reported revenue, including sales to external customers and intersegment sales or transfers is 10 percent or more of the combined revenue, internal and external, of all operating segments b) the absolute amount of its reported profit or loss is 10 percent or more of the greater, in absolute amount of 1) the combined reported profit of all operating segments that did not report a loss or 2) the combined reported loss of all operating segments that did report a loss c) its assets are 10 percent or more of the combined assets of all operating segments.

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+ Details

Property and Equipment (Details Narrative) - USD ($)	12 Months Ended
Property and Equipment (Details Narrative) - USD ($)	Apr. 30, 2023	Apr. 30, 2022
Property, Plant and Equipment [Abstract]
Depreciation	$ 183,000	$ 144,000

Leases (Details Narrative) - USD ($) $ in Millions	12 Months Ended
Leases (Details Narrative) - USD ($) $ in Millions	Apr. 30, 2023	Apr. 30, 2022
Lessee, Operating Lease, Renewal Term	2 years
Lease commencement date	62 months
Operating lease cash flow payments	$ 0.4	$ 0.4
Monroe Township [Member]
Lessee, operating lease, option to extend	The lease includes an initial lease term of seven years which is set to expire in November of 2024, and contains an option to extend the lease for another five years
Lease commencement date	7 years
Houston, Texas [Member]
Lessee, operating lease, option to extend	expire in January of 2024
Lease commencement date	1 year

Operating Segments and Geographic Information (Details Narrative)	12 Months Ended
	Apr. 30, 2023 Segment
Segment Reporting [Abstract]
Number of reportable segments	1

Schedule of Effective Income Tax Rate Reconciliation (Details)	12 Months Ended
	Apr. 30, 2023	Apr. 30, 2022
Income Tax Disclosure [Abstract]
Computed expected tax benefit	(21.00%)	(21.00%)
State income taxes, net of federal benefit	4.00%	5.20%
Federal research and development tax credits	1.90%	(0.60%)
Foreign rate differential
Other non-deductible expenses	(1.10%)	(0.90%)
Proceeds of sale of New Jersey tax benefits	(7.00%)	(7.00%)
Other	1.30%	1.30%
Increase in valuation allowance	22.90%	14.10%
Income tax (benefit)	1.00%	(8.90%)

Consolidated Statements of Comprehensive Loss - USD ($) $ in Thousands	12 Months Ended
	Apr. 30, 2023	Apr. 30, 2022
Income Statement [Abstract]
Net loss	$ (26,326)	$ (18,874)
Foreign currency translation adjustment		(32)
Total comprehensive loss	$ (26,326)	$ (18,906)

- Definition

Amount after tax of increase (decrease) in equity from transactions and other events and circumstances from net income and other comprehensive income. Excludes changes in equity resulting from investments by owners and distributions to owners.

+ References + Details

- Definition

The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

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-Section S99
-Paragraph 1B
-Subparagraph (SX 210.13-02(a)(5))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480097/470-10-S99-1B

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-Subparagraph (b)
-Publisher FASB
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-Section 50
-Paragraph 32
-Subparagraph (f)
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-Topic 260
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 60B
-Subparagraph (a)
-Publisher FASB
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-Topic 280
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-Name Accounting Standards Codification
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Reference 34: http://www.xbrl.org/2003/role/disclosureRef
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+ Details

Leases

12 Months Ended

Apr. 30, 2023

Leases

Leases

(9) Leases

Lessor Information

As of April 30, 2023, the Company had three WAM-V’s leased to customers which have been classified as operating leases per accounting guidance contained within Accounting Standards Codification (“ASC”) Topic 842, “Leases”. The remaining term on these operating leases is less than 2 years.

Lessee Information

Right-of-use asset and operating lease liabilities are recognized based on the present value of future minimum lease payments over the lease term at commencement date. When the implicit rate of the lease is not provided or cannot be determined, the Company uses the incremental borrowing rate based on the information available at the effective date to determine the present value of future payments. Lease terms may include options to extend or terminate the lease when it is reasonably certain that the Company will exercise those options. The renewal options have not been included in the lease term as they are not reasonably certain of exercise. The Company’s operating leases consist of leases for office facilities and warehouse space. Lease expense for minimum lease payments is recognized on a straight- line basis over the lease term and consists of interest on the lease liability and the amortization of the right of use asset.

The Company has a lease for its facility located in Monroe Township, New Jersey that is used as warehouse/production space and the Company’s principal offices and corporate headquarters. The lease includes an initial lease term of seven years which is set to expire in November of 2024, and contains an option to extend the lease for another five years. The lease is classified as an operating lease and is included in right-of-use assets, right-of-use liabilities- current and right-of-use liabilities- long-term on the Company’s Consolidated Balance Sheets.

The Company also signed a new lease in January 2023 located in Houston, Texas for office space for our local employees. The lease term is for 1 year and is set to expire in January of 2024. ASC 842 allows a company an accounting policy election to recognize lease payments within the Consolidated Statement of Operations on a straight-line basis if the lease term is equal to or less than 12 months and not recognize a right-of use asset and lease liability. The accounting policy election is made on the commencement date of the lease. The Company has chosen this election for the Houston lease and classified it as a short-term lease.

The Company also has a lease with the University of California Berkeley in Richmond, California that was assumed as part of the MAR acquisition. The lease is currently a month-to-month lease in accordance with the lease agreement. In accordance with ASC 842, since the remaining lease term at the time of the acquisition of MAR was less than 12 months, the lease was not recognized as a right-of-use asset.

The Company also signed a new lease located in Richmond California for a new office space for MAR which commenced in April of 2023 and will continue for 62 months. The lease is classified as an operating lease and is included in right-of-use assets, right-of-use liabilities- current and right-of-use liabilities- long-term on the Company’s Consolidated Balance Sheets.

Variable lease expenses, if any, are recorded as incurred. The operating lease expense in the Consolidated Statement of Operations was $0.4 million and $0.4 million for the fiscal year ended April 30, 2023 and 2022, respectively.

The components of lease expense in the Consolidated Statement of Operations for the fiscal year ended April 30, 2023 and 2022 was as follows:

Schedule of Operating Lease Costs

	2023		2022
	Fiscal year ended April 30,
	2023		2022
Operating lease cost	$	382	$	368
Short-term lease cost		44		35
Total lease cost	$	426	$	403

Information related to the Company’s right-of use assets and lease liabilities as of April 30, 2023 is as follows:

	April 30, 2023
	(in thousands)

Operating lease:
Operating right-of-use assets, net	$	1,751

Right-of-use liabilities- current		529
Right-of-use liabilities- long term		1,311
Total lease liabilities	$	1,840

Weighted average remaining lease term- operating leases		4.14 years
Weighted average discount rate- operating leases		8.5	%

Total remaining lease payments under the Company’s operating leases are as follows:

	April 30, 2023
	(in thousands)

2024	$	701
2025		494
2026		318
2027		325
Thereafter		362
Total future minimum lease payments		2,200
Less imputed interest		(360	)
Total	$	1,840

Schedule of Components of Property and Equipment (Details) - USD ($) $ in Thousands	Apr. 30, 2023	Apr. 30, 2022
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 2,851	$ 2,030
Less: accumulated depreciation	(1,571)	(1,585)
Property and equipment, net	1,280	445
Equipment [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	783	615
Computer Equipment & Software [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	700	571
Office Furniture And Equipment [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	386	352
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	611	477
Leased buoys And WAMVs [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	371
Construction in Progress [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross		$ 15

Share-Based Compensation Plans

12 Months Ended

Apr. 30, 2023

Share-Based Payment Arrangement [Abstract]

Share-Based Compensation Plans

(13) Share-Based Compensation Plans

In 2015, upon approval by the Company’s shareholders, the Company’s 2015 Omnibus Incentive Plan (the “2015 Plan”) became effective. A total of 1,332,036 shares were authorized for issuance under the 2015 Omnibus Incentive Plan, including shares available for awards under the 2006 Stock Incentive Plan remaining at the time that plan terminated, or that were subject to awards under the 2006 Stock Incentive Plan that thereafter terminated by reason of expiration, forfeiture, cancellation or otherwise. If any award under the 2006 Stock Incentive Plan or 2015 Plan expires, is cancelled, terminates unexercised or is forfeited, those shares become again available for grant under the 2015 Plan. The 2015 Plan will terminate ten years after its effective date, in October 2025, but is subject to earlier termination as provided in the 2015 Plan. At subsequent shareholder meetings, including most recently in January 2023, the shareholders approved an aggregate increase to the 2015 Plan of 3,050,000 shares resulting in total shares authorized for issuance of 4,382,036 as of April 30, 2023. As of April 30, 2023, the Company had 221,446 shares available for future issuance under the 2015 Plan .

On January 18, 2018, the Company’s Board of Directors adopted the Company’s Employment Inducement Incentive Award Plan (the “2018 Inducement Plan”) pursuant to which the Company reserved 25,000 shares of common stock for issuance under the Inducement Plan. In accordance with Rule 711(a) of the NYSE American Company Guide, awards under the Inducement Plan may only be made to individuals not previously employees of the Company (or following such individuals’ bona fide period of non-employment with the Company), as an inducement material to the individuals’ entry into employment with the Company. An award is any right to receive the Company’s common stock pursuant to the 2018 Inducement Plan, consisting of a performance share award, a restricted stock unit award or a stock payment award. On February 9, 2022, the 2018 Inducement Plan was amended to increase the authorized shares by 250,000 to 275,000. As of April 30, 2023, there were 161,487 shares available for grant under the 2018 Inducement Plan.

Stock Options

The Company estimates the fair value of each stock option award granted with service-based vesting requirements, using the Black-Scholes option pricing model, assuming no dividends, and using weighted average valuation assumptions. The risk-free rate is based on the U.S. Treasury yield curve in effect at the time of grant commensurate with the expected life of the award. The expected life (estimated period outstanding) of the stock options granted was estimated using the “simplified” method as permitted by the SEC’s Staff Accounting Bulletin No. 110, Share-Based Payment. Expected volatility is based on the Company’s historical volatility over the expected life of the stock option granted. There were 601,089 and 793,850 shares granted for the periods ended April 30, 2023 and 2022, respectively.

	Fiscal year ended April 30,
	2023			2022
Risk-free interest rate		3.5	%		1.5	%
Expected dividend yield		0.0	%		0.0	%
Expected life (in years)		5.5			5.5
Expected volatility		109.0	%		121.9	%

A summary of stock options under our Stock Incentive Plans is detailed in the following table.

Schedule of Stock Option Activity

	Shares Underlying Options			Weighted Average Exercise Price		Weighted Average Remaining Contractual Term (In Years)
Outstanding as of April 30, 2022		1,110,356		$	2.34		9.2
Granted		601,089		$	0.68
Exercised		—		$	—
Cancelled/forfeited		(182,165	)	$	1.59
Expired		(95	)	$	511.12
Outstanding as of April 30, 2023		1,529,185		$	1.75		8.8
Exercisable as of April 30, 2023		513,077		$	3.22		7.7

As of April 30, 2023, the total intrinsic value of outstanding and exercisable options was approximately zero. As of April 30, 2023, approximately 513,000 additional options were unvested, which had an intrinsic value of zero and a weighted average remaining contractual term of 7.7 years. There was approximately $0.3 million and $0.3 million of total recognized compensation cost related to stock options during each of the fiscal year ended April 30, 2023 and 2022, respectively. As of April 30, 2023, there was approximately $0.7 million of total unrecognized compensation cost related to non-vested stock options granted under the plans. This cost is expected to be recognized over a weighted-average period of 2.3 years.

Performance Stock Options

A summary of performance stock options under our stock incentive plans is detailed in the following table.

Schedule of Stock Option Activity

	Shares Underlying Options			Weighted Average Exercise Price		Weighted Average Remaining Contractual Term (In Years)
Outstanding as of April 30, 2022		210,122		$	2.20		8.8
Granted		—		$	—
Exercised		—		$	—
Cancelled/forfeited		(143,455	)	$	2.93
Outstanding as of April 30, 2023		66,667		$	0.62		8.1
Exercisable as of April 30, 2023		—		$	—

As of April 30, 2023, approximately 66,667 additional options were unvested, which had an intrinsic value of zero and a weighted average remaining contractual term of 8.1 years. There was approximately $0.1 million and $0.1 million of total recognized compensation cost related to performance stock options during each of the fiscal year ended April 30, 2023 and 2022, respectively. As of April 30, 2023, there was approximately $4,000 of total unrecognized compensation cost related to non-vested stock options granted under the plans. This cost is expected to be recognized over a weighted-average period of 0.1 years.

Restricted Stock Units

Compensation expense for unvested restricted stock units is generally recorded based on its market value on the date of grant and recognized ratably over the associated service and performance period. During the year ended April 30, 2023 and 2022, the Company granted 1,608,681 and 827,764 shares, respectively, subject to service-based and market condition vesting requirements.

A summary of unvested restricted stock units under our stock incentive plans is as follows:

	Number of Shares			Weighted Average Price per Share
Issued and unvested at April 30, 2022		827,764		$	1.41
Granted		1,608,681		$	0.75
Vested and issued		(399,429	)	$	1.38
Cancelled/forfeited		(51,022	)	$	1.32
Issued and unvested at April 30, 2023		1,985,994		$	0.89

There was approximately $1.1 million and $0.2 million of total recognized compensation cost related to restricted stock units for the years ended April 30, 2023 and 2022, respectively. As of April 30, 2023, there was $1.1 million of unrecognized compensation cost remaining related to unvested restricted stock granted under our plans. This cost is expected to be recognized over a weighted-average period of 1.4 years.

Schedule of Significant Changes in Contract assets (Details) - USD ($) $ in Thousands	12 Months Ended
	Apr. 30, 2023	Apr. 30, 2022
Account Receivable Contract Assets And Contract Liabilities
Transferred to receivables from contract assets recognized at the beginning of the period	$ (1,768)	$ (190)
Revenue recognized and not billed as of the end of the period	1,534	386
Net change in contract assets	$ (234)	$ 196

Background and Liquidity (Details Narrative) - USD ($) $ in Thousands	12 Months Ended
	Apr. 30, 2023	Apr. 30, 2022
Accounting Policies [Abstract]
Net loss	$ 26,326	$ 18,874
Cash in operations	21,707	21,296
Cash	6,900
Short-term investments	$ 27,790	$ 49,384

- Definition

Amount of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Excludes cash and cash equivalents within disposal group and discontinued operation.

+ References + Details

- Definition

The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

+ References

+ Details

Schedule of Property, Plant and Equipment, Useful Life (Details)	Apr. 30, 2023
Equipment [Member] \| Minimum [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, useful life (Year)	5 years
Equipment [Member] \| Maximum [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, useful life (Year)	7 years
Computer Equipment & Software [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, useful life (Year)	3 years
Office Furniture & Fixtures [Member] \| Minimum [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, useful life (Year)	3 years
Office Furniture & Fixtures [Member] \| Maximum [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, useful life (Year)	7 years
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Property, Plant, and Equipment, Useful Life, Term, Description [Extensible Enumeration]	Useful Life, Lease Term [Member]
Leased Assets [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, useful life (Year)	10 years

Accrued Expenses (Tables)

12 Months Ended

Apr. 30, 2023

Payables and Accruals [Abstract]

Schedule of Accrued Expenses

Accrued expenses consisted of the following at April 30, 2023 and 2022:

Schedule of Accrued Expenses

	April 30, 2023		April 30, 2022
	(in thousands)
Project costs	$	181	$	59
Contract loss reserve		—		328
Employee incentive payments		1,948		266
Accrued salary and benefits		52		60
Professional Fees		—		30
Other		165		134
Accrued expenses total	$	2,346	$	877

Summary of Significant Accounting Policies (Policies)

12 Months Ended

Apr. 30, 2023

Accounting Policies [Abstract]

Basis of Consolidation

(a) Basis of Consolidation

Use of Estimates

(b) Use of Estimates

Business Combinations

(c) Business Combinations

Revenue Recognition

(d) Revenue Recognition

The Company has elected to record taxes collected from customers on a net basis and does not include tax amounts in revenue or costs of revenue.

The below table represents the total revenue recognized under ASC 606 and ASC 842 fiscal years ended April 30, 2023 and 2022:

	Fiscal year ended April 30, 2023						Fiscal year ended April 30, 2022
	ASC 606		ASC 842		Total		ASC 606		ASC 842		Total
	(in thousands)						(in thousands)
Product Line:
WAM-V	$	919	$	667	$	1,586	$	401	$	—	$	401
Buoy		269		—		269		379		—		379
Services		877		—		877		979		—		979
Total	$	2,065	$	667	$	2,732	$	1,759	$	—	$	1,759

Region:
North and South America	$	1,812	$	667	$	2,479	$	1,633	$	—	$	1,633
Europe		—		—		—		19		—		19
Asia and Australia		253		—		253		107		—		107
Total	$	2,065	$	667	$	2,732	$	1,759	$	—	$	1,759

Cash and Cash Equivalents, Restricted Cash, Security Agreements and Investments

(e) Cash and Cash Equivalents, Restricted Cash, Security Agreements and Investments

Cash and Cash Equivalents

	April 30, 2023		April 30, 2022
	(in thousands)
Checking and savings accounts	$	2,874	$	1,815
Money market account		4,009		6,070
Cash and cash equivalents	$	6,883	$	7,885

Restricted Cash and Security Agreements

	April 30, 2023		April 30, 2022
	(in thousands)
Cash and cash equivalents	$	6,883	$	7,885
Restricted cash- short term		65		258
Restricted cash- long term		155		219
	$	7,103	$	8,362

Investments

The following table summarizes the Company’s short term investments as of April 30, 2023 and 2022:

	April 30, 2023						April 30, 2022
Category	Amortized Cost		Unrealized Gains (Losses)		Market Value		Amortized Cost		Unrealized Gains (Losses)			Market Value
	(in thousands)
Corporate Bonds	$	14,776	$	100	$	14,876	$	37,777	$	995		$	38,772
Government Bonds & Notes	$	9,188	$	33	$	9,221	$	9,076	$	(1,022	)	$	8,054
Government Agency	$	3,826	$	25	$	3,851	$	2,531	$	(11	)	$	2,520
Total Short Term Investments	$	27,790	$	158	$	27,948	$	49,384	$	(38	)	$	49,346

Inventory

(f) Inventory

Accounts Receivable

(g) Accounts Receivable

Property and Equipment

(h) Property and Equipment

Description		Estimated useful life

Equipment		5-7 years
Computer equipment & software		3 years
Office furniture & fixtures		3-7 years
Leasehold improvements		Shorter of the estimated useful life or lease term
Leased WAM-V assets		10 years

Foreign Exchange Gains and Losses

(i) Foreign Exchange Gains and Losses

Concentration of Credit Risk

(j) Concentration of Credit Risk

Net Loss per Common Share

(k) Net Loss per Common Share

Share-Based Compensation

(l) Share-Based Compensation

Intangibles

(m) Intangibles

Goodwill

(n) Goodwill

Income Taxes

(o) Income Taxes

Accumulated Other Comprehensive Loss

(p) Accumulated Other Comprehensive Loss

Warranty

(q) Warranty

The Company does not include a right of return on its products other than rights related to standard warranty provisions that permit repair or replacement of defective goods.

Research and Development

(r) Research and Development

Costs related to research and development activities by the Company are expensed as incurred.

Recently Issued Accounting Standards

(s) Recently Issued Accounting Standards