USS Nautilus was the first U.S. Navy submarine to complete a submerged transit beneath the Arctic ice cap.
During Operation Sunshine in 1958, Nautilus travelled from the Pacific Ocean to the Atlantic Ocean under the Arctic ice. Its nuclear propulsion made the journey possible without surfacing for air or refuelling, although navigation and ice conditions forced the crew to abandon an earlier attempt.
The successful passage included the crossing beneath the geographic North Pole on 3 August 1958. It provided valuable evidence that nuclear submarines could use the Arctic as a route between oceans and operate for long periods in one of the world’s most difficult environments.
The achievement is distinct from the later North Pole surfacing by USS Skate. Nautilus remained submerged during the crossing; Skate’s 1959 expedition is remembered for surfacing at the pole.