USS Mercer ( APL - 39 ) The second USS " Mercer " ( APB 39 / IX 502 / APL 39 ) is a of the United States Navy . Originally classified as Barracks Craft APL 39 , the ship was reclassified as Self - Propelled Barracks Ship APB 39 on 7 August 1944 . Laid down on 24 August 1944 by Boston Navy Yard , and launched on 17 November 1944 as " APB 39 " , sponsored by Mrs . Lillian Gaudette , the ship was named " Mercer " , after counties in eight states , on 14 March 1945 , and commissioned on 19 September 1945 , Lt . Comdr . Edward E . Vezey , Jr . , USNR , in command . Service history . New York , 1945 – 1947 . " Mercer " , a barracks ship built on an LST hull , commenced her career of berthing and messing large numbers of naval personnel at New York on 7 November 1945 . Transferred to the Inactive Fleet in January 1946 , she remained at New York until 9 September , when she got underway for Orange , Texas , and remained in duty there until the spring of 1947 . She then headed for Green Cove Springs , Florida , where she was decommissioned on 18 June 1947 , but remained in service with the Florida Group , Atlantic Reserve Fleet . Naples , Rhode Island and Argentia , 1951 – 1956 . She was recommissioned on 12 October 1951 and after a brief overhaul sailed for Norfolk , Virginia , en route to Naples , Italy , where she served as a receiving ship until 1 July 1952 . Returning to the United States on 21 July , she underwent an overhaul and reported to Davisville , Rhode Island , for duty as a barracks ship for Mobile Construction Battalion s . On such duty into late 1955 , " Mercer " was thrice deployed to Argentia , Newfoundland from 19 March to 3 October 1953 , 14 March to 18 October 1954 , and 27 February to 25 July 1955 . Her Seabee duty was interrupted when she sailed to Washington , D . C . , to berth midshipmen of the United States Merchant Marine Academy taking part in President Dwight D . Eisenhower ' s 1953 Inaugural Parade . Upon returning from her 1955 Argentia deployment , " Mercer " sailed to New York for a pre - inactivation overhaul , and on 7 November she sailed for Green Cove Springs where she was decommissioned 17 February 1956 , and once again entered the Reserve Fleet . Eleven years later she was reactivated and taken to Long Beach , California for modernization . Vietnam , 1968 – 1969 . She was recommissioned on 11 May 1968 and on 2 June reported for duty with the Amphibious Force , Pacific Fleet , at San Diego . Within the month she was en route to her ultimate assignment , the Republic of Vietnam where she arrived at Vung Tau on 31 July . Well into 1969 she supported mobile naval units fighting Viet Cong and North Vietnam ese forces operating in South Vietnam . " Mercer " left Vietnam in August 1969 . Sasebo , 1975 – 1980s . Decommissioned and reclassified as Miscellaneous Auxiliary IX 502 , a messing and berthing barge , she was placed in service on 1 November 1975 at the US Naval Ship Repair Facility , Sasebo , Japan . 1980s and 1990s . IX 502 served during the 1980s as a berthing barge at Naval Station San Diego , providing berthing , messing , and classroom accommodation for crews of ships undergoing overhaul . The ship was towed to the Long Beach Naval Shipyard , California , in the early 1990s , where she served the same function until the shipyard closed in 1997 . Return to Sasebo . Reclassified as Barracks Ship ( non - self propelled ) " APL 39 " on 7 March 2001 , " APL 39 " is part of the CincPacFlt Berthing and Messing Program and is berthed at SRF Det . Sasebo , Japan . Awards . USS " Mercer " earned four campaign star s for Vietnam War service , in addition to the Presidential Unit Citation and the Navy Unit Commendation .