In 1775, David Bushnell invented the first submarine . Built of oak beams, it resembled two turtle shells joined together, as pictured on the right. It was known as the American Turtle. Click to see a 300 Kb video of its operation.
Although its attempt to sink the H.M.S. Eagle, the 64 gun flagship of the British fleet, was unsuccessful it represented the birth of the submarine, the most powerful naval weapon in history.

It had air reserves for 30 minutes of underwater operation. It would travel approximately 3 metres below the surface propelled by hand-powered propellers. It would then drill a hole into the hull of the enemy ship and attach a high explosive mine.

John Holland, an Irish patriot, saw a solution to the British naval supremacy in a small submersible vessel. On May 17^th, 1897, Holland, as pictured on the right, displayed his perfected design publicly, hoping to attract government funding. His design included, periscope, torpedoes that could be propelled by compressed air motors, ballast tanks for diving, gasoline engine for traveling on the surface and a battery powered engine for underwater travel.

Holland's submarine spent four hours surfacing, diving and even fired a torpedo which hit its mark at a range of just under 300 metres. The U.S. Navy and the Royal Navy showed little interest, but the German Kriegsmarine were very enthusiastic in the idea. Shortly after Holland's demonstration the Germans purchased the licenses for his design.

Seventeen years later, on September 21, 1914, the German submarine U-9, a larger version of the submarine demonstrated by Holland, sunk three British cruisers with three torpedoes.