|depth finder (děpth) Pronunciation Key
An instrument used to measure the depth of water, especially by radar, sonar, or ultrasound.
device used on ships to determine the depth of water by measuring the time it takes a sound (sonic pulse) produced just below the water surface to return, or echo, from the bottom of the body of water. Sonic depth finders are in operation on practically every important class of ship, naval and merchant, and are also used on small craft.
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