Special Features:

Inavy name is echo depth sounder

Properties:

All the components and items required to operate an electromechanical echo ranging system specifically designed to provide the dual functions of propagating underwater sound energy and of intercepting and presenting intelligence from the reflected portion of the transmission. Secondary functionsmay include underwater communication, listening, monitoring own ship's noise, mine and torpedo detection, depth sounding and the like. For items specifically designed for depth determination, see sounding set, sonar. See also sound ranging set; communication set, sonar and receiver-transmitter, sonar.