1960: The USS Triton, a nuclear-powered radar picket submarine, arrives in Groton, Connecticut, after completing the first completely submerged circumnavigation of Earth. It spends 60 days, 21 hours under water.

The Triton put to sea Feb. 15, and the crew was told to prepare to stay out longer than normal. Still submerged, the boat reached St. Peter and St. Paul Rocks in the mid-Atlantic east of Brazil on Feb. 24, where the men on board were informed of the Navy’s plans.

In the following weeks, Triton rounded Cape Horn, crossed the Pacific and Indian oceans, then slipped past the Cape of Good Hope and into the Atlantic, reaching St. Peter and Paul Rocks on April 10.

The boat did surface once, briefly, to transfer a sick sailor to the heavy cruiser USS Macon, but this was not considered a break in the submerged circumnavigation.

In practical terms, the Triton’s accomplishment demonstrated the submerged endurance capabilities of modern submarines, while enhancing U.S. military prestige. The boat also returned with new oceanographic data. The boat’s commander, Capt. Edward Beach, received the Legion of Merit from President Dwight D. Eisenhower, and the Triton was awarded a Presidential Unit Citation.

Source: U.S. Navy

Photo: Official U.S. Navy Photograph

This article first appeared on Wired.com May 10, 2007.