If you had even a hint of claustrophobia, what happened on this day in 1960 would have left you absolutely speechless. The USS Triton pulled off something no vessel had ever done before — circling the entire Earth without once breaking the ocean's surface, in a daring mission known as Operation Sandblast.

The USS Triton (SSRN-586), a nuclear-powered submarine, quietly etched its name into Cold War history by becoming the first vessel to complete a fully submerged circumnavigation of the globe. Operation Sandblast, as the mission was known, ranks among the most secretive and ambitious naval undertakings of that era. Setting out on February 24, 1960, and wrapping up on April 25, 1960, the submarine spent an astonishing 60 days and 21 hours beneath the waves — a feat that powerfully demonstrated the extraordinary capabilities of America's nuclear submarine fleet.

Spanning more than 26,000 nautical miles, the Triton's underwater odyssey traced a path remarkably similar to the one charted by Ferdinand Magellan over 400 years prior. But here's where the comparison ends: while Magellan's fleet braved the open seas, the Triton stayed completely hidden beneath them. Its advanced nuclear propulsion meant there was never any need to surface, keeping the submarine concealed under the waves for the entirety of its journey. As a showcase of Cold War technological prowess and naval engineering, it was nothing short of extraordinary for anyone who learned of it.

Beyond the engineering achievement, the voyage carried enormous geopolitical weight. With Cold War tensions running high, this remarkable display of prolonged underwater endurance sent a clear message about the power and global reach of America's nuclear submarine force. Captain Edward L. Beach, Jr. commanded the USS Triton throughout the mission, and his crew collected invaluable navigational and oceanographic data along the way. Perhaps most importantly, the voyage proved to the world that U.S. submarines could operate undetected beneath the oceans for months on end.

Fun Facts:

  • The USS Triton (SSRN-586), a nuclear-powered radar picket submarine, was used during the travel.
  • Distance traveled: Over 26,000 nautical miles
  • The entire trip took 60 days and 21 hours submerged
  • The sub closely followed the path of Magellan's 16th-century voyage
  • Commander: Captain Edward L. Beach, Jr., also a decorated WWII submarine officer and author
  • Captain Beach wrote a bestselling account of the mission, titled "Around the World Submerged," which gives a firsthand look at this monumental underwater journey.