Which submarine became the first to reach the North Pole underwater in 1958?

USS Nautilus became the first submarine to reach the North Pole underwater in 1958.

The nuclear-powered American submarine crossed beneath the Arctic ice during Operation Sunshine. It passed over the geographic North Pole on 3 August 1958, demonstrating that nuclear propulsion could support long underwater voyages without atmospheric air for diesel engines.

Nautilus was commissioned in 1954 and was the world’s first operational nuclear-powered submarine. Its nuclear reactor gave it much greater endurance and speed underwater than conventional submarines, which needed to surface or snorkel regularly to recharge batteries.

The submarine is sometimes confused with USS Skate, which surfaced at the North Pole in 1959. Nautilus instead made the earlier under-ice transit and later became a museum ship in Groton, Connecticut.