Echo sounding is a technique used to measure the depth of the sea. This method involves sending sound waves from a ship or a sound source towards the seafloor. When these sound waves hit the seafloor, they bounce back or echo towards the ship, where they are detected by a sonar system. By measuring the time it takes for the sound waves to travel to the seafloor and back, the depth of the sea can be calculated. This technique is commonly used for mapping the topography of the ocean floor, identifying underwater features such as mountains, valleys, and canyons, as well as determining the depth of the water for navigation purposes. Echo sounding is an important tool in marine exploration and research.