Note 6 - Revenue From Contracts With Customers - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended			6 Months Ended
	Jul. 31, 2023		Jul. 31, 2022	Jul. 31, 2023		Jul. 31, 2022
Sale of marine technology products	$ 8,750	[1]	$ 8,713	$ 21,336	[1]	$ 17,800
Transferred at Point in Time [Member]
Sale of marine technology products	8,283		7,976	20,160		16,977
Transferred over Time [Member]
Sale of marine technology products	467		737	1,176		823
Seamap [Member] | Transferred at Point in Time [Member]
Sale of marine technology products	7,103		4,288	17,508		12,281
Seamap [Member] | Transferred over Time [Member]
Sale of marine technology products	458		737	650		823
Klein [Member] | Transferred at Point in Time [Member]
Sale of marine technology products	1,180		3,688	2,652		4,696
Klein [Member] | Transferred over Time [Member]
Sale of marine technology products	9		0	526		0
UNITED STATES
Sale of marine technology products	378		2,333	1,720		4,586
Europe, Russia and CIS [Member]
Sale of marine technology products	2,965		4,082	10,000		8,694
Middle East and Africa [Member]
Sale of marine technology products	4,700		2,042	8,653		4,226
Asia Pacific [Member]
Sale of marine technology products	$ 707		$ 256	$ 963		$ 294

[1] Reflects the condensed consolidated balance sheet as of July 31, 2023 and condensed consolidated statement of operations for the three and six months ended July 31, 2023 and 2023 in the Form 10-Q.