Multibeam echo sounder

A device, usually fixed to the hull of a ship, that emits a beam of “acoustic waves”, and measures the return signal of these sound waves after they are reflected from the seafloor. By calculating the travel time of the sound waves, the water depth can be simultaneously estimated over the entire width of the swathe. Multibeam echo sounders can be used to determine the bathymetry of the oceans and to produce nautical maps. In underwater archaeology, they are used during geophysical surveys to detect large masses, such as metal wrecks protruding from the seabed.