An experimental vessel, the 80-ton, 15.5-metre (51 ft) crewed deep-ocean research submersible was built by Reynolds Metals Company, which was seeking to promote the utility of aluminum.

Aluminaut was based in Miami, Florida, and was operated from 1964 to 1970 by Reynolds Submarine Services, doing contract work for the U.S. Navy and other organizations, including marine biologist Jacques Cousteau.

[3][4] In 1964, Reynolds had the Electric Boat Division of General Dynamics in Groton, Connecticut, build the world's first aluminum submarine.

Aluminum's strength-to-weight ratio exceeds that of steel, so Aluminaut's 6.5-inch-thick (170 mm) shell could withstand pressures of 7,500 pounds per square inch (52 MPa) at the sub's 17,000 ft (5,200 m) maximum diving range.

[citation needed] A one-sixteenth scale model of the final design was built in 1960 and run through stability and pressure tests.

On January 17, 1966, a 1.45-megaton-of-TNT equivalent thermonuclear bomb (Teller–Ulam design) was lost in the Mediterranean Sea during a United States Air Force collision over Palomares, Spain.

[6] The U.S. Navy responded to the coast off Spain with an 18-ship, 2,200-man recovery task force under Admiral William S. "Wild Bill" Guest.

In addition to military ships, the civilian-crewed Aluminaut and deep-sea submersible Alvin were both used to respond to this urgent situation as part of the task force, along with other specialized equipment.

For eighty days the search went on, straining the U.S. relationship with Spain, and giving Soviet propagandists what Time magazine described as "a rich fallout of anti-American gibes".

While Alvin was being lowered over the side of Lulu on October 16, 1968, two steel cables snapped with three crew members aboard and the hatch open.

Lunches left aboard Alvin were found to be soggy but edible, a fact which was tested when a preserved cheese sandwich was nibbled upon by one of the crew.