[2] In mid-April 1915, explorer Ernest Shackleton's ship Endurance, carrying the 27 members of his Antarctic expedition, became locked in the polar ice in the Weddell Sea just off Antarctica.

Shackleton and five others crammed into a lifeboat, the James Caird, sailed across the Scotia Sea for 800 miles (1,300 km), reaching South Georgia two weeks later.

Poor weather prevented them from setting sail again to one of the whaling stations on the island's east side, which were the only human habitation on South Georgia.

It was decided to land a mountain troop of Special Air Service and 42 Royal Marine Commandos on the glacier, to approach Grytviken from the most unlikely direction.

On returning to Antrim, the Wessex 3 (which can be seen at the Fleet Air Arm Museum at Yeovilton, Somerset) held 16 personnel instead of its normal 4 capacity.