When you think about it for a moment, it shall not be surprising that the submarine has been invented by a Dutchman - after all the Dutch the masters of water. The first navigable submarine we know of was built in 1620 by the Dutch innovater Cornelis Drebbel, who was working for the English Royal Navy in that time. The submarine was made of wood covered with leather. Between 1620 and 1624, Drebbel built two more models, of which the last one was the largest with a capacity of 16 men and 6 oars on each side. The third model was demonstrated to King James I and thousands of London spectators. Drebbels boat travelled beneath the Thames for three subsequent hours and swam from Westminster to Greenwich and back at 4-5 meters depth.
Drebbel even took the King on a test dive - making James the first monarch to travel underwater!