The mobile submarine simulator (MOSS) MK70 is a

sonar decoy A sonar decoy is a device for decoying sonar. Most are released from submarines to act as a false target. Submarine decoys The first submarine decoys were the German Bold fitted to U-boats of World War II. These were a pellet of calcium hydr ...

used by

submarine A submarine (or sub) is a watercraft capable of independent operation underwater. It differs from a submersible, which has more limited underwater capability. The term is also sometimes used historically or colloquially to refer to remotely op ...

s of the

United States Navy The United States Navy (USN) is the maritime service branch of the United States Armed Forces and one of the eight uniformed services of the United States. It is the largest and most powerful navy in the world, with the estimated tonnage of ...

. It was a 10-inch vehicle, without an explosive warhead, but able to generate both an active sonar echo and a passive sound signature recorded to be extremely similar to that of the launching submarine. The purpose of MOSS was to create multiple targets all with the same acoustic signature. MOSS was originally developed by Gould until Westinghouse acquired that division. Some current underwater training targets are modeled after MOSS's design. The MOSS first entered service in 1976 and was deployed on all American

ballistic missile submarines A ballistic missile submarine is a submarine capable of deploying submarine-launched ballistic missiles (SLBMs) with nuclear warheads. The United States Navy's hull classification symbols for ballistic missile submarines are SSB and SSBN – t ...

from the 1980s until it was withdrawn in the mid 1990s. Unmanned underwater vehicles Sonar decoys

See also