History
United States
Name	USS Diploma (AM-221)
Builder	Tampa Shipbuilding Company, Tampa, Florida
Laid down	1 July 1943
Launched	21 May 1944
Sponsored by	Mrs. F. J. Erwin, Jr.
Commissioned	15 July 1944
Decommissioned	3 September 1946
Reclassified	MSF-221, 7 February 1954
Fate	Transferred to Mexican Navy, 1962
History
Mexico
Name	ARM DM-17
Acquired	1962
Renamed	ARM Cadete Francisco Márquez (C59), 1994[1]
Namesake	Francisco Márquez
Stricken	2000[1]
Fate	unknown
General characteristics
Class and type	Admirable-class minesweeper
Displacement	650 long tons (660 t)
Length	184 ft 6 in (56.24 m)
Beam	33 ft (10 m)
Draft	9 ft 9 in (2.97 m)
Propulsion	2 × ALCO 539 diesel engines, 1,710 shp (1,280 kW) Farrel-Birmingham single reduction gear 2 shafts
Speed	15 knots (28 km/h)
Complement	104
Armament	1 × 3"/50 caliber (76 mm) DP gun 2 × twin Bofors 40 mm guns 1 × Hedgehog anti-submarine mortar 2 × Depth charge tracks
Service record
Part of:	U.S. Pacific Fleet (1944–1946) Mexican Navy (1962–2000)
Operations:	Battle of Okinawa
Awards:	3 Battle stars

USS Diploma (AM-221) was an Admirable-class minesweeper built for the United States Navy during World War II. She was awarded three battle stars for service in the Pacific during World War II. She was decommissioned in September 1946 and placed in reserve. While she remained in reserve, Diploma was reclassified as MSF-221 in February 1955 but never reactivated. In 1962, she was sold to the Mexican Navy and renamed ARM DM-17. In 1994 she was renamed ARM Cadete Francisco Márquez (C59). She was stricken in 2000, in 2004 she was cleaned of contaminants and sunk as an artificial reef on the west coast of Isla Espiritu Santo, off La Paz BCS, Mexico. She is a popular local dive site, The C59, and is resting on her side at 70'/20m to 30'/9m of depth.

Diploma was launched 21 May 1944 by Tampa Shipbuilding Co., Inc., Tampa, Florida; sponsored by Mrs. F. J. Erwin, Jr.; and commissioned 15 July 1944.

Diploma arrived at Pearl Harbor 12 January 1945 with the disabled U.S. Army freighter FS-318 in tow. The next day she sailed on convoy escort duty to Guam and Eniwetok, returning to Pearl Harbor 17 February. Diploma was underway from Pearl Harbor 23 February for Ulithi where she conducted minesweeping exercises in preparation for the invasion of Okinawa. On 19 March she got underway for Okinawa to engage in pre-invasion minesweeping from 24 March until 1 April and then patrolled during the initial landings. From 17 April to 15 May she was in Ulithi for repairs. After escorting convoys to Guam and Saipan, Diploma returned to Okinawa the last day of May to resume patrolling. From 4 July to 31 July she swept mines in support of the final U.S. 3rd Fleet raids on the Japanese mainland.

After the cessation of hostilities she continued sweeping in the East China Sea-Ryukyus area and in the Tsugaru Straits into Ominato Naval Base at the northern tip of Honshū. Diploma received three battle stars for World War II service.

On 20 November Diploma sailed for the west coast, arriving at San Diego, California, 20 December. She was underway on 5 January 1946 for Mobile, Alabama, and after visits there and at New Orleans, Louisiana, arrived at Orange, Texas, 12 May. Diploma was placed out of commission in reserve there 3 September 1946. She was reclassified MSF-221, 7 February 1955. Transferred to Mexico as DM-17, later renamed Cadete Francisco Marquez (C-59)

The former Diploma was acquired by the Mexican Navy in 1962 and renamed ARM DM-17. In 1994, she was renamed ARM Cadete Francisco Márquez (C59) after Francisco Márquez. She was stricken in 2000, in 2004 she was cleaned of contaminants and sunk as an artificial reef on the west coast of Isla Espiritu Santo, off La Paz BCS, Mexico. She is a popular local dive site, The C59, and is resting on her side at 70'/20m to 30'/9m of depth.

•  This article incorporates text from the public domain Dictionary of American Naval Fighting Ships. The entry can be found here.

• Photo gallery of Diploma at NavSource Naval History