Depth finder and Echosounder

Depth finder noun - Navigational instrument used to measure the depth of a body of water (as by ultrasound or radar).

Echosounder and depth finder are semantically related in sonar topic. In some cases you can use "Echosounder" instead a noun phrase "Depth finder", when it comes to topics like sounder.

Depth finder and echosounder are semantically related in sonar topic. You can use "Depth finder" instead a noun "Echosounder", if it concerns topics such as sounder.