An atmospheric diving suit (ADS) is a small one-person articulated submersible of anthropomorphic form which resembles a suit of amour, 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 Newt suit and the WASP, both of which are self-contained hard suits that incorporate propulsion units. The Newt suit is constructed from cast aluminum (forged aluminum in a version constructed for the US Navy for submarine rescue), while the WASP is of glass-reinforced plastic (GRP) body tube construction. The upper hull is made from cast aluminum.