Fathometer (depth sounder)

A fathometer, or depth sounder, is an electronic device used to measure the distance from a boat or ship to the seabed. It works by emitting ultrasonic sound pulses downward into the water. When these sound waves hit the ocean floor, they bounce back to the device. The fathometer calculates the depth based on the time it takes for the echoes to return, considering the speed of sound in water. This information helps mariners navigate safely, avoid underwater hazards, and understand water depths for anchoring or fishing.