An atmospheric diving suit (ADS) is a small one-person articulated submersible of anthropomorphic form which resembles a suit of armour, with elaborate pressure joints to allow articulation while maintaining an internal pressure of one atmosphere. The ADS can be used for very deep dives of up to 2,300 feet (700 m) for many hours, and eliminates the majority of physiological dangers associated with deep diving; the occupant need not decompress, there is no need for special gas mixtures, and there is no danger of decompression sickness or nitrogen narcosis. Divers do not even need to be skilled swimmers.
Atmospheric diving suits in current use include the Newtsuit and the WASP, both of which are self-contained hard suits that incorporate propulsion units. The Newtsuit is constructed from cast aluminum (forged aluminum in a version constructed for the US Navy for submarine rescue); the upper hull is made from cast aluminum, while the bottom dome is machined aluminum. The WASP is of glass-reinforced plastic (GRP) body tube construction.
In 1715, British inventor John Lethbridge constructed a "diving suit". Essentially a wooden barrel about 6 feet (1.8 m) in length with two holes for the diver's arms sealed with leather cuffs, and a 4-inch (100 mm) viewport of thick glass. It was reportedly used to dive as deep as 60 feet (18 m), and was used to salvage substantial quantities of silver from the wreck of the East Indiaman Vansittart which sank in 1718 off the Cape Verde islands.
The first armored suit with real joints, designed as leather pieces with rings in the shape of a spring (also known as accordion joints), was designed by Englishman W. H. Taylor in 1838. The diver's hands and feet were covered with leather. Taylor also devised a ballast tank attached to the suit that could be filled with water to attain negative buoyancy. While it was patented, the suit was never actually produced. It is considered that its weight and bulk would have rendered it nearly immobile underwater.