USS Agile (AM-421/MSO-421) was an Agile-class minesweeper acquired by the U.S. Navy for the dangerous task of removing mines from minefields laid in the water to prevent ships from passing.
Agile was laid down on 22 February 1954 at Stamford, Connecticut, by the Luders Marine Construction Co. as AM-421; redesignated MSO-421 on 7 February 1955; launched on 19 November 1955; sponsored by Mrs. Alice Donohue; and commissioned at the New York Naval Shipyard on 21 June 1956, Lt. Herbert D. Mills, Jr., in command.
Agile began her first Atlantic Ocean crossing on 12 February 1957, transited the Strait of Gibraltar on the 26th and cruised with the U.S. 6th Fleet for three months. During that time, the ship participated in two amphibious exercises and visited several Mediterranean ports. Among her ports of call were Patras and Athens on the Greek mainland; the Greek islands of Samos, Rhodes, and Crete and Cannes, France. The crisis in Jordan in April kept her in the eastern portion of the Mediterranean for most of her first deployment. After turnover at Rhodes, Agile began the long voyage home on 25 May; and she re-entered Charleston with her division mates on 16 June.
Post-deployment leave and upkeep occupied the ensuing five weeks. On 26 July, the minesweeper got underway for Little Creek, Virginia, to participate in harbor defense and minesweeping exercises. However, damage to her propeller forced her into repairs at the Newport News Shipbuilding & Dry Dock Co. and precluded her participation in the exercises. The repairs ended on 25 September, and the warship departed Newport News, Virginia, that same day. Returning to Charleston five days later, she spent the bulk of October conducting acoustic trials out of her home port.