Commercial sonars are designed for fish finding, depth sounding, and sub-bottom profiling. They typically
generate sound at frequencies of 3 to 200 kHz, with only a narrow frequency band generated by an
individual sonar system. Source levels range from 150-235 dB re 1µPa @ 1 m. Commercial depth
sounders and fishfinders are typically designed to focus sound into a downward beam. Depth sounders and
sub-bottom profilers are operated primarily in nearshore and shallow environments, however, fish finders
are operated in both deep and shallow areas