Submarines and Submersibles Underwater vehicles are called
submersibles, or airtight, rigid diving machines designed for
exploration while completely submerged. Submersibles are either
manned or remotely operated. When designed for warfare,
submersibles are called submarines, possessing streamlined hulls
(frames) made Though submarines seem to be modern inventions,
their origin goes back to the fourth century B.C.E. when Greek
historians said Alexander the Great's soldiers used "diving
bells" for attacking underwater. Probably the first person to
travel horizontally underwater was Dutch engineer Cornelis
Drebbel. Around 1620, Drebbel built submersibles that resembled
two wooden rowboats—one atop the other—made from grease-soaked
leather stretched on a frame with oars stuck through
waterproofed holes. Historians consider Drebbel's vessels the
first practical use of a maneuverable submarine. Submarines
built in the United States, England, France, Germany, and Italy
were larger in size than predecessors, but wer