Scientific and Hydrographic use of the Bathymetric SWATH Survey System

The Bathymetric Swath Survey System (BSSS), in use on the NOAA Ship DAVIDSON, is an important mapping tool for both the scientific and hydrographic user. The 36 kHz system covers the sea floor in a swath of 21 beams, each 5 degrees wide, for a total swath width of 105 degrees. That is equivalent to 2 1/2 times the water depth being surveyed. It is designed for use in water depths up to 600 meters. By overlapping adjacent swaths, one can obtain complete survey coverage of key areas such as navigational corridors. An example is shown of BSSS data from a recent survey of the San Andreas Fault. The BSSS data from that survey were complemented by the simultaneous operation of a 3.5 kHz sub-bottom profiler and the ship´s 100 kHz narrow beam echo sounder.