Diving Bell

A diving bell is a rigid chamber used to carry divers from the surface down to a working depth and back in open water, typically suspended by a cable and lowered and raised by a winch from a surface platform, distinguishing it from a self-propelled submersible. The Greek philosopher Aristotle described divers using a bell-shaped chamber to work underwater as early as the 4th century BC, making the diving bell one of the earliest recorded pieces of underwater work equipment. Diving bells developed into two main types, the open-bottomed wet bell that keeps ambient water pressure inside and the sealed closed bell that can maintain a pressure higher than the surrounding water, and both are still used today to transport commercial and saturation divers to and from deep-sea worksites.