Our First Submarine was a Lemon, in Function and in Form

The first submarine propelled by something other than oars was the Turtle, built in Connecticut in 1775 by David Bushnell as a weapon against the threatening British. The Turtle more closely resembled a lemon, made of wood and covered in tar. The purpose of the Turtle was to drill holes into ships and then place explosive charges in the exposed hulls. But Bushnell and his brother Ezra, the experienced driver of the vessel, had several problems to overcome.
There was no light source in 1775 other than the candle, and since the Turtle had no additional air source every ounce was needed and the candle used up the oxygen more quickly. Benjamin Franklin suggested they use Foxfire, which was a fungus that glowed in the dark. Many test trials were completed by brother Ezra in the Connecticut River and on September 7, 1776, two months after the United States declared itself independent of England, the Turtle was ready for its first mission.
The target was the British flagship, the HMS Eagle, a 64-gun juggernaut of the naval world. The ship was moored off of Liberty Island, the current location of the Statue of Liberty, and the waters were calm. All was ready, the conditions were perfect, except for one thing. Ezra Bushnell, the man who ran all of the tests and knew the inside of the Turtle so well, died the night before. But the mission went on. Army volunteer Sergeant Ezra Lee was given a crash course in driving an underwater lemon and then was quickly sent out to do his job.
Lee approached the hull of the Eagle unnoticed and commenced his drilling, but the spot he chose was metal, not wood. After a second failed attempt the oxygen supply was on empty. Lee had to leave, and in his haste and oxygen-depleted state he unknowingly led his tiny ship vertically as well as horizontally and soon the Turtle was spotted by the enemy. They gave chase and Lee was able to submerge and lose his predators, but somewhere along the way he lost hold of the bomb, which went off in the harbor with a great, explosive bang. No one was injured, but the British saw what was possible and moved their fleet to a more secure location.
If Bushnell and his Turtle had been successful, if the largest, most important of the British ships had been destroyed at the start of the Revolutionary War, the outcome of the war may not have been as close as it turned out to be.