Multibeam echosounder data collected on Southern Surveyor voyage SS2011_V01 using the Simrad EM300 multibeam echosounder to acquire high resolution seafloor bathymetry and backscatter information. This voyage took place in the Southern Ocean during April 2011. Ping rate varied according to depth. Data are stored in Simrad *.all raw format at CMAR and Geoscience Australia (GA). There are 74 files totalling 903 MB of raw data in this dataset. Additional information regarding this dataset is contained in the cruise report for this voyage and/or the data processing report (as available).