Multibeam echosounder data collected on Southern Surveyor voyage SS2011_V05 using the Simrad EM300 multibeam echosounder to acquire high resolution seafloor bathymetry and backscatter information. This voyage took place in the Southern Ocean during August 2011. Ping rate varied according to depth. Data are stored in Simrad *.all raw format at CMAR and Geoscience Australia (GA). There are 653 files totalling 13.6 Gb 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).