"I was obliged to rise up every few minutes to see that I sailed in the right direction."
Sergeant Ezra Lee, pilot of Turtle
In 1775 Britain's North American colonies rebelled against British rule, precipitating a War of Independence. An enthusiastic American patriot, David Bushnell (1742-1824) of Saybrook, Connecticut, devised a secret weapon to counter the might of Britain's Royal Navy. He designed and built a submersible vessel to attack warships in harbor.
Bushnell's Turtle was an oval-shaped vessel of wood and brass, just large enough to hold one person. It had ballast water tanks that were filled to make it dive, then emptied with a hand pump to return to the surface. Two screw propellers, operated by foot pedals and a handle, allowed the operative to maneuver the vessel laterally and vertically underwater. Ingeniously, the inside of the submersible was lined with naturally luminescent wood to provide light for reading the instruments—a compass and a depth meter.
Turtle's weapon was an under water gunpowder charge with a timer, in effect the first sea mine, although Bushnell called it a "torpedo," after a stinging crampfish. A drill was provided for attaching the charge to the hull of a ship at anchor.
Turtle was first sent into action on September 7, 1776. With an army volunteer, Sergeant Ezra Lee, at the controls, it was launched into New York harbor to attack the British flagship, HMS Eagle. Lee successfully brought Turtle up against the underside of Eagle's hull, but failed to attach the charge. Getting the drill to penetrate the ship's copper-sheathed hull while maintaining position in strong currents was beyond Lee's powers. The subsequent fate of Turtle is obscure, but it never achieved a successful attack.
