Who invented the submarine?
History of submarines
Although there were various plans for submersibles or submarines during the Middle Ages, the Englishman William Bourne designed one of the first prototype submarines in 1578. This was to be a completely enclosed boat that could be submerged and rowed beneath the surface. Comprising a completely enclosed wooden vessel sheathed in waterproofed leather, it was to be submerged by using hand operated wooden screw thread adjustable plungers pressing against flexible leather bags located at the sides in order to increase or decrease the volume of water to adjust the buoyancy of the craft. The sketch (left) suggests that the depth adjustment was by means of a crankset projecting above the surface. There is no obvious accommodation for crew. The first submersible to be actually built in modern times was constructed in 1605 by Magnus Pegelius. Its fate was to become buried in mud. In 1596 the Scottish mathematician and theologian John Napier wrote in his "Secret Inventions" the following: "These inventions besides devises of sayling under water with divers, other devises and strategems for harming of the enemyes by the Grace of God and worke of expert Craftsmen I hope to perform."
It's unclear whether or not Napier ever carried out his plans. Henry Briggs, who was professor of mathematics at Gresham College, London, and later at Oxford, was a friend of Napier, whom he visited in 1615 and 1616, and was also an acquaintance of Cornelius Van Drebbel, a Dutchman in the service of James I of England, who designed and built the first successful submarine in 1620. Hence, it is not impossible that it was because of the interest taken by Napier in the submarine that Briggs came in touch with Drebbel.
Isla San Telmo
Subsequently, Jim Delgado of the Vancouver Maritime Museum investigated the wreck. A local fisherman told Delgado about the wreck that he had observed during the low tide, a rusted and weed covered metal body off the coast of St. Thelmo. Delgado saw this wreck sitting on the coastline of St. Thelmo, but did not believe the fisherman's conjecture that the wreck was of a Japanese submarine that operated in the Panama Canal during World War II. He explored the wreck, recorded its dimensions, but could not link it to any known vessels as it resembled more of a science fantasy vessel. After five years, it was identified as the "Sub Marine Explorer", an underwater craft designed by Julius H. Kroeh, a German engineer who also reportedly died because of this vessel, that was one of the world's first submarines. It is now established that it was a pioneering vessel, of which a few more examples are also stated to have been preserved, which did underwater explorations during the 19th century. Richard Wills, an American Civil War submarine specialist, confirmed that details about the Sub Marine Explorer were published in a scientific article in 1902. Investigations revealed that there were several technical problems in the vessel which had resulted in several tragedies and the submarine was an "iron coffin" in the Pacific Ocean bed. As the story of the submarine was widely circulated, Delgado set out to explore the submarine further, in 2002 and 2004.