The first one.......

Turtle was the world's first submarine used in battle. It was invented in Connecticut in 1775 by American Patriot David Bushnell as a means of attaching explosive charges to ships in a harbor. Governor Trumbull recommended the inventor to George Washington and although the commander in chief had doubts he provided funds and support for developing and testing the machine.

The submarine was designed as a naval weapon, and it was meant to drill into a ship's hull and plant a keg containing 130 pounds of gunpowder, which would be detonated by a time fuse. Much testing was done by the inventor's brother, Ezra Bushnell, in the waters of the Connecticut River.

Named for its shape, Turtle resembled a large clam as much as a turtle; it was about 8 feet long (according to original specs), 6 feet (1.8 m) tall, and about 3 feet (0.9 m) wide, consisting of two wooden shells covered with tar and reinforced with steel bands. It submerged by allowing water into a bilge tank at the bottom of the vessel and ascended by pushing water out through a hand pump, similarly to the use of spear sack tanks in modern submarines, and was propelled vertically and horizontally by hand-cranked propellers, the first recorded use of the screw propeller for ships. It also had two hundred pounds of lead which could be released in a moment to increase buoyancy. It was manned and operated by one person. It contained enough air for about thirty minutes and had a speed in calm water of about three miles per hour.

Six small pieces of thick glass in the top were the only source of natural light. After Bushnell pondered the problem of lighting the inside of the ship and after learning that using a candle would hasten the use of the limited oxygen supply of the air inside, he solicited the help of Benjamin Franklin who cleverly hit upon the idea of using bioluminescent foxfire to provide illumination for the compass and depth meter. The light given by the material was said to be sufficient at night, though likely dimmer than expected, because the ship was cooled by the surrounding sea water and the metabolic rate of poikilothermic, heterotrophic organisms is temperature-dependent.

Thus he (David Bushnell) gave the life to a under water weapon, which is now grown into a giant to destroy a whole ship and even also the harbors. Thus it can be also said as the “Tiger of the oceans”…