During the 1940s and 1950s, the Navy's need for a deep-water test facility grew urgent enough that in 1958 the Chief of Naval Operations convened an advisory group to scout locations worldwide. They needed a trench deep enough to simulate open-ocean warfare, calm enough for precise acoustic measurement, and close enough to the mainland for practical logistics. The Tongue of the Ocean checked every requirement. Its flat bottom descends gradually from 3,600 feet in the south to 6,600 feet in the north, providing varied depth profiles. Islands and coral reefs seal it from open-ocean disturbances on all but the northern end. The year-round tropical climate allows continuous operations with no seasonal shutdown. A joint U.S.-U.K. agreement signed in 1963, with Bahamian government concurrence, granted the Americans development rights on Andros Island's eastern coast. Under the same agreement, the Royal Navy received equal access to the facility.

Construction began in March 1964 on the Main Base and downrange tracking stations scattered along Andros's eastern shore. The first officers and sailors arrived by Navy LST in August 1965 -- no commercial infrastructure existed to receive them. Commander G. P. Barney became the first permanent Officer-in-Charge that October, and AUTEC was officially dedicated on April 14, 1966. The electronics installation, a massive undertaking involving underwater hydrophone arrays and surface tracking systems, ran from fall 1965 through fall 1966. RCA Service Company won the first maintenance and operations contract in September 1966. Meanwhile, a temporary mainland headquarters opened at Orlando Air Force Base before relocating to West Palm Beach, chosen for its airport, seaport, and proximity to Andros. On February 26, 1967, Admiral E. J. Fahy commissioned AUTEC as an operational field activity, presenting Captain L. L. Jackson, Jr. with orders as its first commanding officer.

AUTEC operates three distinct test ranges within the Tongue of the Ocean. The Weapons Range, which became operational first in 1966, runs roughly parallel to Andros's eastern coast and is the largest and most versatile, capable of tracking dozens of underwater objects at once. Sonar Communications Sets and Bi-Directional Communications Nodes provide underwater voice coverage, while HF, UHF, and VHF radio systems blanket the surface. The Acoustics Range followed in 1968, designed for precision sonar testing in the trench's exceptionally quiet waters. The FORACS Range handles additional calibration and tracking work. Above the surface, radars and systems like the Hyperbolic In-Air Tracking System extend coverage to 500 nautical miles and 70,000 feet, monitoring the airspace where anti-submarine warfare scenarios play out. The typical task remains what it has been since the beginning: certifying submarine captains and their crews, then testing the weapons they would carry into combat.

In 1969, the Navy named AUTEC's major buildings after fallen servicemembers, turning the remote base into a quiet memorial. Shafer Brothers Hall honors Benjamin and John Shafer, Chief Electrician's Mates lost at sea in 1963. Jacobson Hall commemorates George W. Jacobson, Sr., a Chief Motor Machinist's Mate who earned the Silver Star for helping capture a German submarine off French West Africa in June 1944. Mackey Hall remembers Harry E. Mackey, Jr., an Aviation Machinist's Mate killed in action in November 1943 and posthumously awarded the Distinguished Flying Cross for operations off French Morocco. Momsen Hall bears the name of Vice Admiral Charles B. Momsen, inventor of the Momsen Lung, an early submarine escape device. Danenhower Hall honors Lt. Commander Sloan Danenhower, who commanded the original USS Nautilus on an Arctic expedition in 1931 -- his father, John Wilson Danenhower, had commanded the ill-fated USS Jeannette decades before.

AUTEC occupies an odd place in the cultural imagination. Tom Clancy stationed his fictional defector Marko Ramius there in The Cardinal of the Kremlin, working under the alias Mark Ramsey after the events of The Hunt for Red October. An episode of NCIS built its plot around the facility. Conspiracy theorists have sometimes called it an "underwater Area 51," though the reality is more prosaic: it is a working test range where submarine crews drill and weapons are calibrated, far from public view but thoroughly documented in Navy records. The facility also conducts biological research in the surrounding waters, studying marine life in the deep trench. From the air, AUTEC's presence on Andros is modest -- a few clusters of buildings along the eastern coast, antenna arrays, and piers jutting into turquoise water. The real infrastructure lies beneath the surface, in the hydrophone arrays and tracking systems threaded along the bottom of one of the Atlantic's most remarkable geological features.