This year marks 235 years when the first military submarine” Turtle" was designed and built in the U.S.A.

The idea of building a submarine had existed since ancient times. In the fifteenth century, Italian genius Leonardo da Vinci had even drawn up a plan for the ship's structure. Later, feeling uneasy about the invention's application for military purposes, he destroyed the drawing. Namely war affairs forced some countries to return to the idea of the submarine. The first to implement the idea were Americans who fought in War of Independence with British (1775-1783).

Great Britain, by combining the best of their warships, controlled the New York harbor. Americans had to get rid of this blockade somehow. Then, in the summer of 1775, in the seaside town Saybrook, Connecticut, passionate American Revolutionary patriot and gifted engineer, David Bushnell, completed the construction of his own submarine (Latin sub = under, marina = sea), intended for sinking British ships.

The ship drawings that survived helped to restore the exact image of "Turtle". This was a slightly more than 2 meters high "barrel". It was made of carefully proportioned oak beams. By way of sealing, the hull was bolted with steel rims covered with resin. Submersion and the rise to the surface were secured by a manual pump. It regulated the ballast water level. Leaden ballast, mounted at the bottom of the vessel, served for the sudden rise to the surface.

The submarine was able to accommodate only one person. He had a sufficient stock of air for half an hour. D. Bushnell had also installed a snorkel, in other words, a breather, whose tube, when vessel immersed, would protrude above the water. The vessel was driven horizontally and vertically by screws. They were whirled by crew member's hands. The steering was operated by his leg pressing the pedal.
Successfully tested, in the summer of 1776, the ship was secretly brought to New York. "Turtle" had to attack the British frigate "Eagle" armed with 64 cannons. This war flagship stood anchored at the Staten Island.

At night of 6 September, "Turtle", controlled by Sergeant Lee Izra, was dragged by a boat closer to the British frigates. Vigorously laboring the driving screw handles, Sergeant immersed under the British military ship and tried to drill a hole in the bottom to place explosives. The bottom of the ship appeared to be covered with metal panels. Running out of air, Lee was forced to briefly come out. The second attempt to attach explosives also failed. Exhausted by failures, Izra Lee emerged to the surface and struggled to swim toward the shore. In order to escape quickly, he liberated himself from the 113 kilogram-mine which he carried. After a while, when the activation mechanism went off, the mine exploded, which quite scared the British sailors. English ships immediately raised anchors and moved farther away from the islands surrounding New York. 

Despite the failure, "Turtle" was the first swallow to predict the birth of the submarine. Connecticut River museum and some other maritime museums have a replica of the first submarine built by surviving drawings.