Diving bell

A diving bell is a rigid chamber used to transport divers to depth in the ocean. The most common types are the wet bell and the closed bell.

The wet bell is a cable-suspended chamber, open at the bottom like a moon pool structure, that is lowered underwater to operate as a base or a means of transport for a small number of divers. The pressure of the water keeps the air trapped inside the bell. They were the first type of diving chamber. Unlike a submarine, the diving bell is not designed to move under the control of its occupants, nor to operate independently of its tether.