submersible Small craft for underwater exploration, research, or engineering. The bathyscaphe, invented in the 1940s by Swiss scientist Auguste Piccard, had a spherical chamber attached to a much larger hull, which functioned as a buoyancy control device. From the late 1950s, a new generation of submersibles evolved for engineering and research work. A typical craft has a spherical passenger capsule capable of withstanding water pressure down to c.3600m (12,000ft). Attached to this is a structure containing batteries, an electric motor with propeller, lighting, a mechanical arm for gathering samples, and other technical equipment.

sub·mers·i·ble / səbˈmərsəbəl/ • adj. designed to be completely submerged or to operate while submerged.• n. a small boat or other craft of this kind, esp. one designed for research and exploration.

submersible Underwater vehicle, used for oceanographic investigation or offshore engineering. These small submarines may be manned or unmanned.