Bathyscaphe vs. Bathysphere — What's the Difference?

A bathyscaphe ( or ) is a free-diving self-propelled deep-sea submersible, consisting of a crew cabin similar to a bathysphere, but suspended below a float rather than from a surface cable, as in the classic bathysphere design.The float is filled with gasoline because it is readily available, buoyant, and, for all practical purposes, incompressible. The incompressibility of the gasoline means the tanks can be very lightly constructed, since the pressure inside and outside the tanks equalises, eliminating any differential.

The Bathysphere (Greek: βαθύς, bathus, "deep" and σφαῖρα, sphaira, "sphere") was a unique spherical deep-sea submersible which was unpowered and lowered into the ocean on a cable, and was used to conduct a series of dives off the coast of Bermuda from 1930 to 1934. The Bathysphere was designed in 1928 and 1929 by the American engineer Otis Barton, to be used by the naturalist William Beebe for studying undersea wildlife.

A free-diving deep-sea vessel consisting of a large flotation hull with a crewed observation capsule attached to its underside, usually capable of reaching the deepest parts of the ocean.

A deep-sea research and exploration vessel consisting of a spherical chamber in which persons are lowered by a cable from a ship at the surface.

A self-propelled deep-sea diving submersible for exploring the ocean depths, consisting of a crew cabin similar to a bathysphere suspended below a float filled with a buoyant liquid such as petrol.

A spherical steel deep-diving chamber with perspex windows, in which persons are lowered to the depths by a cable to study the oceans and deep-sea life; the precursor to the bathyscaphe

Navigable deep diving vessel for underwater exploration

A spherical deep diving apparatus (lowered by a cable) for underwater exploration; it is constructed with a strong steel shell to withstand high pressures at the ocean bottom.

Spherical deep diving apparatus (lowered by a cable) for underwater exploration