David Bushnell designed Turtle during the American Revolution as a one-person submersible intended to attach an explosive charge to British warships.
Bushnell studied at Yale and experimented with the ability of gunpowder to explode underwater.
Turtle used a wooden enclosed hull, hand-operated propulsion, ballast water, pumps, a rudder, and a detachable weight for emergency buoyancy.
The operator had only a limited air supply and had to control depth, direction, and propulsion manually in darkness and current.
The weapon was an external timed explosive intended to be attached to an enemy ship after the operator bored or screwed into the hull.
On September 6, 1776, Ezra Lee used Turtle in New York Harbor in an attempt to attack a British warship.
The attack failed because Lee could not attach the explosive as intended and eventually abandoned the attempt.
Bushnell’s own later report, George Washington’s correspondence, and other contemporary documents confirm that the machine existed and was tried, even though later patriotic retellings sometimes exaggerate the result.
Turtle did not sink an enemy vessel, but it demonstrated a combination of underwater propulsion, depth control, and offensive purpose that made it a major milestone in submarine history.
For TransitSatellite, the attack should be represented as an attempted mission with uncertain exact underwater path, not as a successful combat strike.