An early aviator, Wilkins accompanied the explorer-ethnologist Vilhjalmur Stefansson in the Canadian Arctic (1913–16), was second in command of the British Antarctic expedition to Graham Land (1920–21), and also was naturalist on Sir Ernest Shackleton's last Antarctic expedition (1921–22). In 1926 he began a series of trial flights to test the feasibility of air exploration of the then unknown Arctic region north of Point Barrow, Alaska. On April 16, 1928, he and his copilot flew over unknown seas from Point Barrow to the Svalbard (Spitsbergen) archipelago north of Norway, completing the 2,100-mile (3,400-kilometre) journey in 20 ¹/₂ hours. For this feat he was knighted. In the Antarctic (December 1928), he flew 600 miles (970 km) south from Deception Island, across Graham Land, and discovered several new islands. In 1931 he took the U.S. submarine Nautilus and navigated it under the Arctic Ocean to latitude 82°15′ N. He was the manager of Lincoln Ellsworth's U.S. Antarctic expedition (1933–39) and subsequently acted as consultant and geographer to the U.S. armed services.