The Mark 37 torpedo is a torpedo with electrical propulsion, developed for the US Navy after World War II. It entered service with the US Navy in the early 1950s, with over 3,300 produced. It was phased out of service with the US Navy during the 1970s, and the stockpiles were sold to foreign navies.
Mark 37 torpedo at the German Marine Museum Wilhelmshaven
Israeli Mark 37E torpedo
Sonar is a technique that uses sound propagation to navigate, measure distances (ranging), communicate with or detect objects on or under the surface of the water, such as other vessels.
French F70 type frigates (here, La Motte-Picquet) are fitted with VDS (variable depth sonar) type DUBV43 or DUBV43C towed sonars.
Sonar image of the Soviet Navy minesweeper T-297, formerly the Latvian Virsaitis, which was shipwrecked on 3 December 1941 in the Gulf of Finland
Bubble clouds shown under the sea. From ref.
Variable depth sonar and its winch