Data acquisition was performed using a multibeam sonar system Simrad EM-120 from Kongsberg. Raw data are delivered within Simrad current multibeam vendor format.Raw multibeam sonar data, format SIMRAD EM-120 (ALL), packed with ZIP. SIMRAD raw data can be processed i.e. with the software packages CARIS HIPS/SIPS, Caraibes or with the open source software package MB-System (http://www.ldeo.columbia.edu/res/pi/MB-System/).In order to download data, please request access from Laura Robinson (laura.robinson@bristol.ac.uk).