What is an echo sound?

An echo sound (also known as echosounding or echo sounding) is a technique used to determine the depth of water by measuring the time it takes for a sound pulse to travel from a ship or sonar device to the seabed and back again. The speed of sound in water is known, so by measuring the time taken for the sound pulse to return, the depth of the water below the ship can be calculated.

Echo sounding is commonly used in hydrography to create depth maps of the ocean floor, lake beds, and other bodies of water. It is also used in various applications such as underwater navigation, fish finding, and submarine detection.

One of the limitations of echo sounding is that it can only measure the depth directly below the ship's position, so multiple measurements are needed to create a complete map of the seabed. Additionally, factors such as temperature, salinity, and pressure can affect the speed of sound in water and introduce errors in the depth calculations.