Accordingly, having made ready the James Caird, his largest lifeboat, for the voyage, at midday on 24th April, the very last day before the pack ice closed in again, Shackleton and five others - Worsley, Crean, McNeish, McCarthy and Vincent - set off through the Drake Passage - a name to bring dread even to seasoned mariners - in the almost impossible hope of making landfall on South Georgia, eight hundred miles away, and summoning help from the whaling stations there.
This journey involved a crossing of the world's most inhospitable ocean in the depths of Antarctic winter. The boat was buffeted by mountainous and tempestuous seas. Ice built up on the decking, fifteen inches (750mm) deep, threatening to overturn the James Caird. Hour by hour, frostbitten and numbed with cold, they had to chip away from the vessel. At other times they were forced to bale for dear life. Their only solace was four hourly hot meals and the glimmer of a tiny primus stove. Their discomfort, hunched below in the James Caird's cramped hold, must have been absolute.
But given Shackleton's leadership, all six men's sturdy seamenship and the amazing skills of New Zealander Frank Worsley, skipper of the Endurance, in charting a route for the James Caird by direct reckoning with only four sightings of the sun for Worsley to observe their position (April 26, May 3, 4 and 7 - the rest was dead reckoning) - they won through. After sixteen terrible days at sea, the James Caird sighted land at midday on Monday 8 May 1916.
All was by no means to prove easy, however, even now they had completed 800 miles. The boat arrived off South Georgia in hurricane conditions, and only at 5 p.m. on Wednesday 10th did they eventually manage to land, after tacking violently to make their way into a small, inaccessible inlet. Had they failed to make it, or had they overshot the island, Shackleton, his crew and the James Caird would have been either smashed to pieces and or swept beyond South Georgia, to be lost in mid-Atlantic.
They had travelled fifteen hundred miles since the Endurance had been crushed. With the James Caird beached in King Haakon Bay to the west, help now lay only some twenty miles away, at the whaling stations on the east of the island. The mountainous interior had never been penetrated before. Previous attempts had been defeated by the severity of the elements and the only available map, charted largely by Captain Cook, showed merely the outline of the coast.
As Shackleton's three man group, consisting of himself, Frank Worsley and Tom Crean, set off, they were ill-prepared for climbing and had little means to prepare for the glaciers, crevasses and snow storms that lay ahead.
But in the end, Shackleton's proverbial luck held. In no more than thirty-six hours and against incredible odds the three of them crossed the island on the only moonlit night before bad weather closed in again, and arrived at the whaling station of Stromness.
It took four more months and four attempts with help from the Norwegians, and from Uruguay and Chile, before Shackleton finally managed to negotiate a way through the pack ice aboard the steam tug Yelcho, lent to him by the Chilean government, to rescue his remaining twenty-two men.
That boat journey aboard the James Caird was a supreme act of human courage. Not a single man of Shackleton 's original twenty-eight men was lost. And though Endurance was lost, the James Caird survives to this day as a living reminder of an act of remarkable courage in the heroic age of exploration.