A bitter and challenging journey ensued, and the exhausted men landed on Elephant Island 6 days later April 15th 1916; it had been almost 497 days since they last stood on land. In these conditions, Shackleton knew they were in a perilous situation, no passing ships or rescue could be expected. Shackleton decided to try to reach help, using one of the boats. The nearest port was Stanley in the Falkland Islands, 570 nautical miles (1,100 km; 660 mi) away, but was made unreachable by the prevailing westerly winds. A better option was to head for Deception Island, 200 nautical miles (370 km; 230 mi) away at the western end of the South Shetland chain. Although it was uninhabited, Admiralty records indicated that this island held stores for shipwrecked mariners, and was also visited from time to time by whalers. However, reaching it would also involve a journey against the prevailing winds—though in less open seas—with ultimately no certainty when or if rescue would arrive. After discussions with the expedition’s second-in-command, Frank Wild, and ship’s captain Frank Worsley, Shackleton decided to attempt to reach the whaling stations of South Georgia, to the north-east. This would mean a longer boat journey of 700 nautical miles (1,300 km; 810 mi) across the Southern Ocean, in conditions of rapidly approaching winter, but with the help of following winds it appeared feasible. Shackleton thought that “a boat party might make the voyage and be back with relief within a month, provided that the sea was clear of ice, and the boat survive the great seas”.
Source: wikipedia