Standard diving dress

Standard diving dress (also known as hard-hat or copper hat equipment, or heavy gear) is a type of diving suit that was formerly commonly used for all underwater work which required more than breath-hold duration, and included marine salvage, civil engineering, pearl shell diving and other commercial diving work, and similar naval diving applications, though has largely been superseded by lighter and more comfortable equipment.

Standard diving dress consists of a diving helmet made from copper and brass or bronze, an air hose from a surface supplied diving pump, a waterproofed canvas suit, diving knife, and weights to counteract buoyancy, generally on the chest, back and shoes. Later models were equipped with a diver's telephone for voice communications with the surface.

Some variants used rebreather systems to extend the use of gas supplies carried by the diver, and were effectively self-contained underwater breathing apparatus, and others were suitable for use with helium based breathing gases for deeper work. Divers could be deployed directly by lowering or raising them using the lifeline, or could be transported on a diving stage. Most diving work using standard dress was done heavy, with the diver sufficiently negatively buoyant to walk on the bottom. Standard diving dress is also sometimes known in the US as a Diver Dan outfit from the television show of the same name.

In 1405, Konrad Kyeser described a diving dress made of a leather jacket and metal helmet with two glass windows. The jacket and helmet were lined by sponge to "retain the air" and a leather pipe was connected to a bag of air. A diving suit design was illustrated in a book by Vegetius in 1511.

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