In May 1960, the nuclear-powered U.S.S. Triton returns to the States after a three-month "shakedown" (or test) cruise, during which it became the first vessel on Earth to complete a submerged circumnavigation. Interesting fact: The ship was run by Commander Edward L. Beach, author of the best-selling novel Run Silent, Run Deep (about submarine warfare during WWII).
Photo: Yale Joel./Time & Life Pictures/Getty Images