Atmospheric diving suit  An atmospheric diving suit (ADS) is a small one-person articulated anthropomorphic submersible 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 for many hours, and eliminates the majority of significant physiological dangers associated with deep diving; the occupant need not decompress, there is no need for special gas mixtures, nor is there danger of decompression sickness or nitrogen narcosis. Divers do not even need to be skilled swimmers, but the disadvantage is limited dexterity. Atmospheric diving suits in current use include the Newtsuit, Hardsuit and the WASP, all of which are self-contained hard suits that incorporate propulsion units. The hardsuit 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 in length with two holes for the diver's arms sealed with leather cuffs, and a viewport of thick glass. It was reportedly used to dive as deep as , and was used to salvage substantial quantities of silver from the wreck of the East Indiaman , which sank in 1719 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. Lodner D. Phillips designed the first completely enclosed ADS in 1856. His design comprised a barrel-shaped upper torso with domed ends and included ball and socket joints in the articulated arms and legs. The arms had joints at shoulder and elbow, and the legs at knee and hip. The suit included a ballast tank, a viewing port, entrance through a manhole cover on top, a hand-cranked propeller, and rudimentary manipulators at the ends of the arms.