USS F-2 (SS-21)

USS F-2 (SS-21), an F-class submarine, was named Barracuda when her keel was laid down by Union Iron Works of San Francisco, California, but was renamed on 17 November 1911. She was launched on 19 March 1912 sponsored by Miss A. R. Rolph, daughter of James Rolph, the mayor of San Francisco, and commissioned on 25 June 1912 with Lieutenant (junior grade) F. L. Chew in command.

Service history
F-2 joined the 1st Submarine Group, Pacific Torpedo Flotilla, in operations between San Diego, California, and San Pedro, California, the Flotilla's base. She continued to play an important part in developing tactics and coordinating the use of undersea craft with the fleet during an extended training period in the Hawaiian Islands from August 1914-November 1915.

After lying in ordinary at Mare Island Naval Shipyard from 16 March 1916 – 13 June 1917, F-2 became flagship of Division 1, Submarine Force, Pacific Fleet. Returning to operations out of San Pedro, she participated in surface and submerged exercises, torpedo-proving practice, experiments in balancing at various depths, and trained prospective crews of new submarines. On 18 September 1919, she was placed in reserve commission at San Pedro to be used in elemental school work until decommissioned at Mare Island on 16 March 1922. She was sold on 17 August.