Multibeam Echo Sounder (MBES)

A multibeam echo sounder maps a wide swath of seafloor in one pass by forming many narrow acoustic beams across track, giving full-coverage bathymetry instead of a single depth line. Swath width is typically three to five times water depth, so deep-water surveys cover ground quickly while shallow work needs dense, overlapping lines. Accurate soundings depend on a measured sound-velocity profile, motion (heave, roll, pitch) compensation, and tidal reduction to chart datum.