ABSTRACT: .As sonic waves propagate very well in water, acoustic methods are therefore the most valuable tool for sea bed - reconnaissance. Side scanning sonar is a powerful tool for precise and detailed investigation, of sea floor» for both, geological, and geotechnical purposes on continental shelves and in. deeper waters., Ultra sonic pulses (frequency range:: 30-100 kHz) are laterally transmitted at. regular` time, intervals, by one or two groups of transducers fitted in a tow `"fish."`,. The beam is a very narrow in the horizontal plane (I to 2°) and wider in. the vertical plane (10 to 40°). As the ship moves forward,, the sonic beam sweeps the sea floor. "Lateral sonars have no penetration and give only the visible details of the sea floor. The tool, is an. effective support in. the bathymetry,, sea floor1 geology,, sea floor engineering search (harbor and dredging studies, platform site investigation, cable and pipeline route selection.).,