A Brief History of the
USS Grayback (SS/SSG/APSS/LPSS-574)

Construction of the USS Grayback (SS-574) was authorized in 1953.  The keel was laid 1 July 1954 at the Mare Island Naval Shipyard, Vallejo, California and launched 2 July 1954 (Sponsored by Mrs. John J. Moore, widow of the last CO of the first Grayback SS-208) and commissioned 7 March 1958.
The Grayback was initially designated as an attack diesel submarine but was converted into a guided missile submarine (SSG-574) capable of firing the Regulus II sea to surface missiles in 1958.  The Grayback successfully launched the first successful, submarine launched, Regulus missile in September 1958. On 9 February 1959 Grayback departed Mare Island, CA for her permanent home base and arrived in Pearl Harbor, HI on 7 March 1959.  The Regulus missile program ended in 1964 and the USS Grayback was withdrawn from active service.
A second conversion was authorized in 1967, and the conversion began at the Mare Island Naval Shipyard November 1967. The conversion was originally estimated at $15.2 million but actually was $30 million.  She was re-classified from a SSG to LPSS 30 August 1968 (never officially designated APSS). During conversion her sail was extended 10 feet, auxiliary tanks #3 and #4 were added to the forward position of the engine room, the missile chambers were converted to carry 67 embarked troops and SEAL swimmer delivery vehicles (SDV), and a diver’s decompression chamber was constructed in the starboard hanger. By adding the auxiliary tanks to the engine room her length was extended 12 feet to an overall length of 334 feet.
The Grayback was decommissioned for the second time on 15 January 1984 at Subic Bay Naval Station in the Republic of the Philippines. After decommissioning, the USS Grayback was given the honor to make it’s last and final dive in the South China Sea on 13 April 1986 where the USS Grayback remains today on eternal patrol.