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