A Brief History of Site One:

In the autumn of 1959 the US Government presented the problem of providing forward servicing facilities for the first SSBN Squadron in the UK. Studies were made of all the suitable places to base a refit facility and it was decided in July 1960 the Holy Loch should be the site. The Holy Loch was a Royal Navy Submarine base during World War II and the Firth of Clyde was one of the Royal Navy’s major submarine areas, Site One as the base was known, comprised of three major commands, plus the Naval Support Activity.

Submarine Squadron 14 arrived in the Holy Loch on 3 March 1961. The number of submarines being supported by Squadron 14 varied over the years and the measure of that is that on 2 April 1987 the 2500th Ballistic Missile Deterrent Patrol was completed by USS Mariano G Vallejo (SSBN 658).

  The Submarine Tender USS Proteus (AS 19) arrived on 3 March 1961. Five days later the USS Patrick Henry (SSBN 599) arrived, and Proteus commenced the 1st Site One refit.
In January '63 the Proteus was relieved by the USS Hunley (AS 31).
In August '66 the Hunley was relieved by the USS Simon Lake (AS 33).
In May '70 the Simon Lake was relieved the USS Canopus (AS 34).
In November '75 Canopus was relieved by the USS Holland (AS 32).
In January '82 the Holland was relieved by Hunley, returning for a 2nd tour. 
Finally, in June '87 the Hunley was relieved by the Simon Lake [for her 2nd tour] who served until March '92.

  The Dry Dock, USS Los Alamos (AFDB 7), was towed to Scotland in '61, and assembled in six months. Over a 30 year span,  Los Alamos completed over 2800 submarine docking operations.

With the reduction in European tension and the end of the Cold War it was announced on 6 February 1991 that the Holy Loch Base would close, and in March 1992 the last US Navy ship sailed out, thus ending  thirty one years of American presence in the Dunoon area.