Depth finder and Depth gauge

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

Depth gauge and depth finder are semantically related in sounder topic. In some cases you can use "Depth gauge" instead a noun phrase "Depth finder".

Depth gauge noun - A gauge for measuring the depth of grooves or holes or other concavities.

Depth finder and depth gauge are semantically related in sounder topic. You can use "Depth finder" instead a noun phrase "Depth gauge".