Designs for underwater boats or submarines date back to the 1500s and ideas for underwater travel date back even further. However it was not until the 19th century that the first useful submarines began to appear.
By Mary Bellis, About.com Guide
|David Bushnell's Turtle Submarine||Robert Fulton's Submarine||Horace Lawson Hunley & Submarine||The Confederate Submarine H.L. Hunley|
|The Alligator Submarine||Intelligent Whale Submarine||USS Holland (SS-1)||Submarine built by Simon Lake|
|The First U.S. Navy Submariners||US Submarines AL9, AL11||US Submarine L1||Typical WW II Submarine Layout|