A bathyscape or bathyscaphe is a self-propelled deep-sea diving submersible, consisting of a crew cabin similar to a bathysphere suspended below a float filled with a buoyant liquid such as petrol. Propulsion is provided by battery-driven electric motors.
The first bathyscape was FNRS-2, built in Belgium by Auguste Piccard.
Piccard's second Bathyscape was Trieste, and was purchased by the US Navy in 1957. In 1960 Trieste set an unbeatable world record by diving to the bottom of the Challenger Deep, deepest point in the Marianas Trench and believed to be the deepest point in the world's oceans.
See also Timeline of underwater technology.