From 1914 to 1916, he served as Sir Ernest Shackleton's second-in-command on the Imperial Trans-Antarctic Expedition in the "Endurance" ship. After she sank, he was left in charge of 21 men on desolate Elephant Island as Shackleton and a crew of five undertook an epic open-ocean voyage to South Georgia aboard the lifeboat James Caird in order to seek rescue. For more than four months, from 24 April to 30 August 1916, during the Antarctic winter, Wild and his crew waited on Elephant Island, surviving on a diet of seal, penguin and seaweed.