Multibeam echo-sounder (multibeam) emits a sound wave in the transverse direction of the sailing direction up to 75 degrees to the vertical. This gives a complete coverage of the seabed equivalent to 3-7 times the water depth. A multibeam with a maximum opening angle of 120 ° will at water depths of 100 m on each survey line, be able to cover a corridor on the sea bed of (3.4 x 100 m) 340 m.
Multibeam is therefore much more efficient compared to the single-beam echo-sounder, especially if you want to make a hydrographic survey with 100% seabed coverage. Unlike the single-beam echo-sounder, that emits a single wide beam at the seabed, the multibeam is capable of receiving several separate beams. These beams (sound waves) are received in a fan-shaped pattern, enabling the system to collect depth profiles across the sailing direction.