Tritech 325 kHz sidescan for sale.
Technical data can be obtained from:http://www.tritech.co.uk/products/products-sidescan_towfish.htm
Towfish comes with 150 meter of 7mm steel cable, which means it can be operated from smaller boat down to 100 m.
Towfish is connected to laptop by means of SKIM-100 interface unit ( info can found at trietch website) and runs on seanet software which latest version can be downloaded from tritech site.
Price: 4000 USD.
Photos of the unit and sample images are available.