Segment and Customer Information (Details) (USD $)	3 Months Ended								12 Months Ended
	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2011
Sales to external customers	$ 17,921,000	$ 11,243,000	$ 14,410,000	$ 14,268,000	$ 15,457,000	$ 12,993,000	$ 14,588,000	$ 9,572,000	$ 57,842,000	$ 52,610,000	$ 38,858,000
Intersegment sales									0	0	0
Depreciation and amortization									1,670,000	1,628,000	1,219,000
Adjustment of contingent earnout liability	500,000	0	0	0	4,500,000	0	0	0	500,000	4,500,000	0
Income (loss) before income taxes									10,191,000	4,877,000	7,975,000
Segment assets	83,086,000				82,714,000				83,086,000	82,714,000	87,740,000
Goodwill	17,227,000				17,227,000				17,227,000	17,227,000	17,227,000
Fixed asset additions									761,000	1,031,000	361,000
Seismic Energy Sources [Member]
Sales to external customers									22,971,000	19,311,000	18,149,000
Intersegment sales									0	0	0
Depreciation and amortization									210,000	157,000	202,000
Adjustment of contingent earnout liability									0	0	0
Income (loss) before income taxes									4,041,000	4,085,000	4,335,000
Segment assets	23,140,000				19,985,000				23,140,000	19,985,000	22,212,000
Goodwill	0				0				0	0	0
Fixed asset additions									217,000	831,000	213,000
Underwater Cables and Connectors [Member]
Sales to external customers									17,453,000	15,473,000	15,391,000
Intersegment sales									318,000	162,000	137,000
Depreciation and amortization									296,000	266,000	258,000
Adjustment of contingent earnout liability									0	0	0
Income (loss) before income taxes									7,111,000	5,594,000	5,899,000
Segment assets	18,757,000				15,990,000				18,757,000	15,990,000	15,395,000
Goodwill	7,679,000				7,679,000				7,679,000	7,679,000	7,679,000
Fixed asset additions									409,000	102,000	83,000
Seismic Energy Source Controllers [Member]
Sales to external customers									2,700,000	2,482,000	2,743,000
Intersegment sales									612,000	420,000	422,000
Depreciation and amortization									225,000	289,000	287,000
Adjustment of contingent earnout liability									0	0	0
Income (loss) before income taxes									884,000	721,000	1,006,000
Segment assets	5,716,000				6,272,000				5,716,000	6,272,000	6,072,000
Goodwill	3,278,000				3,278,000				3,278,000	3,278,000	3,278,000
Fixed asset additions									9,000	7,000	12,000
Underwater Robotic Vehicles [Member]
Sales to external customers									14,718,000	15,344,000	2,575,000
Intersegment sales									0	0	0
Depreciation and amortization									920,000	897,000	453,000
Adjustment of contingent earnout liability									500,000	4,500,000	0
Income (loss) before income taxes									2,097,000	(1,883,000)	(618,000)
Segment assets	22,724,000				21,421,000				22,724,000	21,421,000	19,319,000
Goodwill	6,270,000				6,270,000				6,270,000	6,270,000	6,270,000
Fixed asset additions									126,000	91,000	53,000
Corporate Headquarters and Eliminations [Member]
Sales to external customers									0	0	0
Intersegment sales									(930,000)	(582,000)	(559,000)
Depreciation and amortization									19,000	19,000	19,000
Adjustment of contingent earnout liability									0	0	0
Income (loss) before income taxes									(3,942,000)	(3,640,000)	(2,647,000)
Segment assets	12,749,000				19,046,000				12,749,000	19,046,000	24,742,000
Goodwill	0				0				0	0	0
Fixed asset additions									$ 0	$ 0	$ 0