USS Alacrity (AM-520/MSO-520) was an Ability-class minesweeper acquired by the United States Navy for the task of removing mines that had been placed in the water to prevent the safe passage of ships.

The third ship to be named Alacrity by the Navy, MSO-520 was laid down on 5 March 1956 at Sturgeon Bay, Wisconsin, by the Peterson Builders; launched on 8 June 1957; sponsored by Mrs. Henry J. Armstrong, the wife of Capt.

Near the end of that assignment, in late April 1965, civil war erupted in the Dominican Republic, as supporters of exiled President Juan Bosch instituted a military uprising to seize power from the ruling civilian junta.

The resultant strife—the city of Santo Domingo became a battleground—saw the commitment of American marines and paratroopers; Alacrity spent almost the entire month of May helping to evacuate foreign nationals and supporting the troops of an inter-American force sent to restore order.

After five months with the U.S. 6th Fleet engaged in training exercises and port visits, the minesweeper headed back to the United States on 11 October.

She entered the "Middle Sea" late in August and spent September and the first week in October steaming in the western Mediterranean and making port visits.

She returned to Charleston on 27 October and, except for a week at sea for special operations in the middle of December, spent the remainder of the year in her home port.

Early in December, she returned to the vicinity of Port Canaveral, Florida, to assist in gathering data during the Apollo 17 moon shot.

During November and early December, she conducted refresher training in the West Indies before returning to Charleston on the 10th to begin the annual holiday leave and upkeep period.