To quantify the winter diving behaviour and vertical habitat use of adult female Antarctic fur seals (Arctocephalus gazella) we tracked females using Wildlife Computers Time-Depth Recorders (TDRs). Females were captured towards the end of the lactation period (March/April) and the TDR was attached dorsally to the fur approximately 10 cm anterior to the rump using a two-part epoxy. TDRs were retrieved just prior to or after giving birth the following season. Data files were extracted from the tags using the Wildlife Computers software Instrument Helper.