Reconstructed plan of the USS Alligator submarine by James P. Christley in 1978, based on his research. Launched on the 1st of May 1862, the USS Alligator was the US Navy's first submarine. It was designed by French engineer Brutus de Villeroi (1794-1874). USS Alligator measured 14 metres in length and was originally propelled by oars. The oars were eventually replaced with a hand-cranked screw propeller. The submarine was in service during the American Civil War. THE USS Alligator sunk in 1862 after one of the lines holding it to its mother vessel USS Sumpter during a storm off Cape Hatteras, North Carolina, USA.