Turtle (also called American Turtle) was the world's first submersible vessel with a documented record of use in combat. It was built in 1775 by American David Bushnell as a means of attaching explosive charges to ships in a harbor, for use against Royal Navy vessels occupying American harbors during the American Revolutionary War. Connecticut Governor Jonathan Trumbull recommended the invention to George Washington, who provided funds and support for the development and testing of the machine.
 
These superb 3D files were created by Randy Sanders and come scaled to 1/12. It builds into a beautiful display model, or, scaled up, this boat would be a great candidate for a creative individual to RC. 

Hull comes in one solid piece, but by adjusting your printer settings to something like 7 or 8 walls, you can print them hollow without any issue.