The Navy One-Man One-Atmosphere Diving System (NOMOADS) was an atmospheric diving suit modified and tested by the U.S. Navy in the 1980s and early 1990s.

NOMOADS was a modification of the commercial atmospheric diving system JIM. The JIM suit was developed in the 1960s by Mike Humphrey and Mike Barrow of the British commercial firm Underwater Marine Equipment Limited (UMEL). Their development efforts were driven by the oil industry, which had begun working at depths greater than those that human divers in ambient pressure suits could work. By 1972, the JIM suit was in use by the oil industry for inspection of offshore drilling equipment, location and reocvery of anchor chains, bottom searches, and still photography.

The U.S. Navy tested a JIM-3 suit in 1975 to investigate its capabilities. It determined that ADS like JIM were viable underwater tools for salvage work and submarine rescue missions. The Navy’s experiments with JIM spurred the development of Navy ADS. In 1978, Dr. Arthur Bachrach initiated a biomedical assessment study of JIM-4, the sucessor to the JIM-3. The research report Dr. Bachrach produced in 1981 defined the concept of a one-atmosphere diving suit and and offered useful background information for the future NOMOADS program. Engineer Michael Troffer with Naval Coastal Systems Center (NCSC) ran engineering studies of NOMOADS and identified many potential mission areas, including search, location, recovery, salvage, rescue work, underwater construction, explosive ordnance disposal, and saturation diving support.

The major difference between NOMOADS and a JIM suit was the torso material: Navy engineers swapped JIM’s magnesium alloy torso for one made of carbon-fiber reinforced plastic (CFRP). They believed CFRP would be lighter and stronger than magnesium alloy. The CFRP torso was tested and evaluated extensively by NCSC for use in deep submergence systems.

The two NOMOADS suits ordered by the Navy were based on a late-stage JIM suit design, which featured a large, clear acrylic dome. This afforded NOMOADS operators far greater visibility compared to the four small viewports found on JIM-3 and JIM-4 suits.

NOMOADS had a maximum depth capability of 2,000 FSW, a maximum bottom time of 40 hours, and the capability to return to the surface from 1,000 FSW in about 10 minutes. Its one-atmosphere system afforded a dramatic advantage over saturation diving: whereas a saturation diver would need more than nine days of decompression after returning from 1,000 FSW, a NOMOADS operator needed no decompression time and ran no risk of decompression sickness.

NOMOADS was scheduled to reach Initial Operational Capability in FY 1994, but was never placed into Navy service. The successful development of the NewtSuit ADS rendered NOMOADS obsolete.