Operation Keyhole was a British special operation on Thule Island in the South Sandwich Islands during Operation Corporate in the 1982 Falklands War. The operation took place from 19–20 June 1982. Ten prisoners (one civilian and nine military personal) were evacuated to the tanker RFAOlmeda, accompanied by HMS Yarmouth. They departed for South Georgia. The Argentine Base Uruguay was closed and the buildings sealed to make them weatherproof. The other ships of Operation Keyhole (HMS Endurance and the MS Salvageman) followed and were back at Cumberland East Bay/South Georgia by 24 June 1982. No deaths or injuries were sustained on either side.
A Royal Marines team were landed on Thule Island covertly to observe Argentine activities. The harsh conditions on the island with an air temperature of minus 20 degrees Celsius and a gale gusting to 60 miles per hour, the chill factor caused an effective drop to −52 degrees. Under the threat of the Royal Marines party on the island and the ships cruising in front of the Argentine Base and several helicopters flying to the Argentine base a white flag was raised. The Endurance people who were forced to lower the Union Flag on South Georgia on 3 April hoisted now the Union Flag on Thule Island.