Until the closure of Charleston Naval Shipyard, modern, nuclear submarines were a common sight in the harbor of Charleston, South Carolina. NAVWPNSTA CHASN is located on the west bank of the Cooper River in the southeast portion of Berkeley County, 25 miles from Charleston and 13 river miles from the Atlantic Ocean.
On 30 September 1958, the Office of the SECDEF approved construction of a POLARIS missile assembly facility near Charleston, South Carolina. Major components of the tactical POLARIS missile were to be shipped there, assembled, checked out, and outloaded on FBM submarines or stored for future outloading. The facility was to be on dormant government property near Charleston, South Carolina, some 17 miles up the Cooper River from the Atlantic Ocean. The largely undeveloped pine forest and marsh site had been an Army ordnance depot during World War II. The Navy acquired the 5,185 acre property in 1954, adding it to the adjacent Naval Ammunition Depot. Construction crews broke ground in December, only 4 months after site selection. ADM Raborn briefly viewed the Naval Weapons Annex, as it was called at the time, in July of 1959. Being on the Cooper River provided access to direct loading of missiles on SSBNs. Some 36 magazines built by the Army during the 1940's were modified and updated, and a large handling crane was installed at Pier Bravo of the Naval Ammunition Depot. The facility was known as the Naval Weapons Annex, a tenant of the Naval Ammunitiion Depot, Charleston, South Carolina. It was commissioned on 29 March 1960. By 1960, the first Polaris Missile Facility Atlantic (POMFLANT) was constructed.
The POMFLANT facility provided the initial out load of a submarine. After a submarine completed its patrol, it returned to an assigned refit site for crew exchanges, supplies, etc. Each refit site had a submarine tender assigned to provide services. The original sites in the Atlantic were site No. 1 at Holy Loch, Scotland (9 March 1961); site No. 2 at Rota, Spain (24 February 1964); and Site No. 4 at Charleston, South Carolina (28 July 1965) (a few miles down the Cooper River from POMFLANT). A site No. 3 was established on December 1964 in the Pacific at Apra Harbor, Guam, to service the POLARIS SSBNs. The original SSBNs in the Pacific were outloaded with POLARIS A3 at POMFLANT. The USS Daniel Boone (SSBN-629) became the first of these SSBNs assigned to the Pacific fleet on 21 August 1964, and began the first Pacific operational patrol on 25 December 1964. The USS Proteus (AS-19) was the original tender assigned at Guam. It was also the first tender assigned at Holy Loch and at Rota. It was not until April 1965 that a Pacific SSBN was outloaded at POMFPAC, Bangor, Washington.