This is processed Conductivity, Temperature, Depth (CTD) data from the Marion Island Relief Voyage on the SA Agulhas II Voyage 007, 10 April to 16 May 2013.The 2013 Marion Relief Voyage 007 on board South Africa’s new polar research and supply vessel, the SA Agulhas II, afforded yet another opportunity to conduct multi-institutional (DEA, DAFF, UCT, SAEON, Rhodes University) and multi-disciplinary ship-based oceanographic research that focused on links and interactions between air and sea, ocean physics, biogeochemistry, plankton and benthic communities and island-based top predators. The overall aim is to establish an oceanographic observation and monitoring system directed by South African research institutions in support of South Africa’s needs – and where possible, the global requirements of the Southern Ocean Observation System (SOOS), CCAMLR, ACAP, etc., by documenting ship-board observations in the oceanic environment around the Prince Edward Islands in a holistic manner, from the sea floor, through water column and food-web dynamics, to air-sea interactions and their respective role in the general global thermohaline circulation realm.With the recent declaration – on 5 April 2013 – of the Prince Edward Islands (PEIs) as South Africa’s first offshore Marine Protected Area (MPA), the outcomes of this cruise will contribute toward an integrated view and a better understanding of the functioning of the combined island/marine PEI ecosystem. This dataset was processed using older standards which may not align with international best practices and the standards currently adhered to by the Department of Forestry, Fisheries and the Environment (DFFE). The Department is re-processing and replacing data to ensure everything has the same format and is of the same quality and datasets will be marked as obsoleted once that is done. As such the user assumes the entire risk related to the use of these data in its current state and format. DFFE disclaims all warranties of the data whether expressed or implied, including without limitation, any warranties of merchantability or fitness for a particular purpose. For any concerns regarding the data, the user may decide to liaise with the listed PIs who will share their insight on the data quality, where possible. It is also strongly recommended that the user liaises with the listed PIs regarding their proposed projects to mitigate against duplication of research efforts.