The South Georgia force, Operation Paraquet, under the command of Major Guy Sheridan RM, consisted of Marines from 42 Commando, a troop of the Special Air Service (SAS) and Special Boat Service (SBS) troops who were intended to land as reconnaissance forces for an invasion by the Royal Marines. All were embarked on RFA Tidespring. First to arrive was the Churchill-class submarine HMS Conqueror on 19 April, and the island was over-flown by a radar-mapping Handley Page Victor on 20 April.
The first landings of SAS troops took place on 21 April, but—with the southern hemisphere autumn setting in—the weather was so bad that their landings and others made the next day were all withdrawn after two helicopters crashed in fog on Fortuna Glacier. On 23 April, a submarine alert was sounded and operations were halted, with Tidespring being withdrawn to deeper water to avoid interception. On 24 April, the British forces regrouped and headed in to attack.
On 25 April, after resupplying the Argentine garrison in South Georgia, the submarine ARA Santa Fe was spotted on the surface by a Westland Wessex HAS Mk 3 helicopter from HMS Antrim, which attacked the Argentine submarine with depth charges. HMS Plymouth launched a Westland Wasp HAS.Mk.1 helicopter, and HMS Brilliant launched a Westland Lynx HAS Mk 2. The Lynx launched a torpedo, and strafed the submarine with its pintle-mounted general purpose machine gun; the Wessex also fired on Santa Fe with its GPMG. The Wasp from HMS Plymouth as well as two other Wasps launched from HMS Endurance fired AS-12 ASM antiship missiles at the submarine, scoring hits. Santa Fe was damaged badly enough to prevent her from diving. The crew abandoned the submarine at the jetty at King Edward Point on South Georgia.
With Tidespring now far out to sea, and the Argentine forces augmented by the submarine’s crew, Major Sheridan decided to gather the 76 men he had and make a direct assault that day. After a short forced march by the British troops and a naval bombardment demonstration by two Royal Navy vessels (Antrim and Plymouth), the Argentine forces surrendered without resistance. The message sent from the naval force at South Georgia to London was, “Be pleased to inform Her Majesty that the White Ensign flies alongside the Union Jack in South Georgia. God Save the Queen.” The Prime Minister, Margaret Thatcher, broke the news to the media, telling them to “Just rejoice at that news, and congratulate our forces and the Marines!”