Speed 15.5 k
Armament 2 3"
The fourth Pontiac, a refrigerator ship built by Nakskov Skibs. A/C, Nakskov, Denmark in 1937, was operated as Australian Reefer by J. Lauretzen, Esbjerg, Denmark, between New York and South America until after the occupation of Denmark by Nazi forces. Taken over by the US Maritime Commission in the summer of 1941 under the authority of Public Law 101, 77th Congress and Executive Order 8771 6 June 1941, she was renamed Pontiac and operated by U.S. Lines between New York and Australia and New Zealand until 5 February 1942. After voyage repairs she was transferred to the Navy on an indefinite time charter basis, 11 May 1942, and commissioned as Pontiac (AF-20), 12 May 1942.
Following conversion and shakedown, Pontiac, assigned to Service Force, Atlantic, departed Norfolk 15 June 1942 on her first Argentia run. On 15 July she completed that run at Boston, whence she continued to carry supplies to the Maritime Provinces and Newfoundland through 1943. Between late January and May 1944 she conducted sugar runs between Norfolk and Trinidad, Guantanamo Bay and San Juan, then returned to Boston to resume runs to Argentia and, in June, to Iceland. She completed a quick run to Bermuda in early August, then returned to the Boston-Argentia route before undertaking her last Caribbean run from New York 7 September. On 25 September she arrived at Norfolk from San Juan, made a trip to Bermuda and on 16 November returned to Boston to resume carrying stores to Nova Scotia and Newfoundland. For the next two months she alternated voyages to Argentia with runs to Bermuda and on 29 January 1945 departed Boston for her last run to Canada.
On the 30th, while in heavy seas off Halifax, her hull was damaged by a loose paravane. She began taking water in her forward compartments and sank in 40' of water off MacNab Island. Raised on 17 February, she was towed to Halifax for temporary repairs. On 14 March she arrived at Norfolk, where she decommissioned 20 May 1945. She was returned to the Maritime Commission on the 21st and was struck from the Navy List 2 June 1945.