echo sounder
echo sounder — noun
1. a device on a ship or boat that sends sound signals toward the bottom of the sea
a device on a ship or boat that sends sound signals toward the bottom of the sea and measures how long they take to come back, so that it can show the water depth or find things under the surface
Tomás checked the echo sounder as the fishing boat crossed the shallow reef.
check the echo sounder during navigation
The echo sounder on the research ship showed a sudden drop in the seabed.
Before lowering the anchor, Nila studied the echo sounder to find a safe depth.
A loud warning from the echo sounder told the crew about underwater rocks ahead.
- sonar
a broader term for any system that uses sound waves underwater; an echo sounder is a specific type of sonar used mainly for depth measurement
- depth sounder
a near-synonym; 'depth sounder' focuses on measuring depth, while 'echo sounder' can also be used for detecting underwater objects
- fish finder
a type of echo sounder designed for finding fish; more common in recreational boating
用法筆記
This sense also covers the more general description of an instrument that determines water depth by sound-wave reflection.