History
United States
Name	USS Alacrity
Builder	Collingwood Shipyards Ltd., Collingwood
Launched	4 September 1942
Acquired	6 January 1942
Commissioned	10 December 1942
Decommissioned	4 October 1945
Stricken	24 October 1945
Homeport	Charleston, South Carolina
Fate	Sold to Italy, 1947
General characteristics
Class and type	Action class
Type	Patrol boat
Displacement	1,375 long tons (1,397 t)
Length	205 ft (62 m)
Beam	33 ft (10 m)
Draft	14 ft 7 in (4.45 m)
Speed	16.5 kn (19.0 mph; 30.6 km/h)
Complement	90
Armament	two 3 in (76 mm) dual purpose gun mounts, two 20 mm gun mounts and two depth charge tracks

USS Alacrity (PG-87) was an Action-class patrol boat acquired by the United States Navy for the task of patrolling American coastal waters during World War II.

The gunboat was constructed in Collingwood, Ontario, Canada by the Collingwood Shipyard, Ltd. as the British Flower-class corvette HMS Cornel (K-278). It was transferred to the U. S. Navy on 6 January 1942; launched on 4 September 1942; and commissioned at Collingwood on 10 December 1942. She was the second ship to be named Alacrity by the U.S. Navy.

World War II

By 31 December, the gunboat had moved to Sorel, Quebec, where she remained into March 1943. On 3 March, she got underway to descend the St. Lawrence River, bound ultimately for Boston, Massachusetts. On 5 March, she stopped at Quebec, Canada, and remained there for two months. Alacrity resumed her voyage on 5 May and arrived at the Boston Navy Yard Annex on 12 May. She remained there until sometime in mid-July, when she sailed for Bermuda and shakedown training in the waters surrounding that island group. She completed shakedown on 15 August and arrived in New York City three days later. After a round-trip voyage apiece to Norfolk, Virginia, and Boston, Alacrity entered the navy yard at Boston for post-shakedown repairs on 21 September.

East Coast operations

She got underway again on 25 September and began escorting ships between New York City and the Caribbean. For the next eight months, the gunboat screened coastal merchant traffic on the New York-to-Guantánamo Bay, Cuba circuit. Early in May 1944, she added Key West, Florida, to her itinerary, but soon thereafter resumed her New York-Guantánamo Bay shuttles exclusively. In May 1945, she ceased voyages to Cuba when she was reassigned from the Atlantic Fleet to the Eastern Sea Frontier. For the remainder of the war, Alacrity served along the east coast—first at Staten Island, then at New York, and – by mid-July – at Charleston, South Carolina. By 1 August 1945, although still based at Charleston, she had been reassigned to the 6th Naval District.

Post-war decommissioning

She was still at Charleston when placed out of commission on 4 October 1945. Her name was struck from the Naval Vessel Register on 24 October. She was transferred to the War Shipping Administration on 22 September 1947 for final disposition.