Platelet ice is a particular sea ice type that is prevalent in McMurdo Sound, probably due to the proximity of the Ross Ice Shelf. There are many details about the formation of platelet ice which are unknown and the study focused on investigating the conditions of the water column when this sea ice type appears. The temperature and salinity close (35 to 60cm) to the ice water interface was ... measured on four occasions near Arrival Heights, the Dellbridge Islands and near Cape Evans. The structure of the ice and isotopic content was analysed. Conductivity temperature (CT) measurements were made near the ice-water interface, conductivity temperature depth (CTD) were made in deep water and flow measurements were made at Cape Evans, Tent Island and Hut Point. Ice cores and water samples were also taken at the three sites during October. Hut Point was also sampled. Salinity measurements, isotope analysis and sections were carried out on the ice cores. Time-lapse video images were made of a growing platelet crystal at the Tent Island site. Thin sections were taken from ice cores to determine the structure of the sea ice. These observations together with the CTD, CD, isotope, salinity and current data will begin to give a picture of the platelet ice growth processes.