SS 304 Spira

The SS 304 Spira is a high-resolution scanning sonar based on the SM 600 commercial fish-finding sonar, but designed for use on patrol ships as small as 150 tons.

The sonar can be used for detection of submarines and for minehunting. The transducer is mounted in a fixed, streamlined, glass-reinforced plastic hull dome that can withstand speeds up to 40 knots.

The sonar generates 17 simultaneous, overlapping receiving beams; the resulting beam is fan-shaped and covers 85...