"Hissem" saw varied duty in 1963. After two tours of picket duty she acted as command ship during the search for lost submarine 16–21 April. A month as school ship for sonar training at Key West, Florida was followed by two more days of duty on "Thresher" search operations 27–28 June. Taking up new duties, "Hissem" sailed 12 August for New Zealand and Operation Deepfreeze, the Navy's continuing effort at exploration and scientific work in Antarctica. The radar picket ship operated between the continent and New Zealand as a navigational beacon and rescue ship for flights to and from the Navy's air facility at McMurdo Sound.