.ALL files correspond to the mutlibeam echo sounder data collected with Merian's EM122 system. The nominal sonar frequency is 12 kHz with an angular coverage sector of up to 150° and 864 soundings per ping. The EM122 has a dual swath capacity, hence one ping consist of two swathes of up to 432 soundings each. The dual swath capacity increases the along track resolution of the multibeam data. The typical depths in our investigation area are between 500 and 5000 m water depth, allowing spacing bathymetry grid resolution of about 30 m to 200 m across and along, given survey velocities between 4.5 and 12 kn. The achievable swath width on a flat bottom will normally be up to six times the water depth. However, we limited the swath width to 15 km and 65° in order to guarantee good resolution in across track direction in deep water. Preliminary grids of the data (.grd) created during the research survey are made available for the bathymetry (MSM47finalgrid.grd, WGS84, Geographic) and backscatter data (MSM47finalgrdsss.grd, WGS84 Geographic).