This dataset relates to geophysical marine data collected onboard the RRS James Clark Ross (JR71) during 2002, which built on swath bathymetry and TOPAS survey undertaken on the JR59 cruise in 2001. Data was collected using Kongsberg-Simrad EM120 multibeam swath bathymetry and a TOPAS sub-bottom profiler. Data was collected as part of a project was to reconstruct the Late Quaternary dynamics of the Antarctic Peninsula Ice Sheet in Marguerite Bay and to compare sedimentation and ice-rafted debris records with the Larsen Ice Shelf area, on the other side of the Antarctic Peninsula. The mapping of streamlined sedimentary bedforms on the outer shelf has allowed the dimensions of a former fast-flowing ice stream present at the Last Glacial Maximum to be defined. This, in turn, enabled estimates of the past magnitude of ice flow through this glacial system to be calculated.