HMAS Diamantina ( K377 ) HMAS " Diamantina " ( K377 / F377 / A266 / GOR266 ) , named for the Diamantina River in Queensland , is a River class frigate that served the Royal Australian Navy ( RAN ) . Constructed in the mid - 1940s , " Diamantina " was active from 1945 until 1946 , was placed in reserve , then was recommissioned as a survey ship from 1959 until 1980 . Following her second decommissioning , the frigate was preserved at the Queensland Maritime Museum as a museum ship . She was the last World War II - era frigate to leave RAN service , and of the 151 River class frigates constructed for 19 navies worldwide , " Diamantina " is the only one preserved as a museum ship . Design and construction . " Diamantina " had a displacement of 2 , 120 tons fully loaded , or 1 , 420 standard displacement tons . She was equipped with two triple expansion engines driving twin screws at 5500 l . h . p . She had a range of at , with a top speed of . " Diamantina " was laid down on 12 April 1943 at Walkers Limited in Maryborough , Queensland . She was launched on 6 April 1944 , and commissioned into the RAN at Hervey Bay , Queensland on 27 April 1945 carrying pennant number K377 . She was named for the Diamantina River in Queensland , and was one of eight River Class frigates built for the RAN during World War II . Operational history . 1945 - 1946 . " Diamantina " provided fire support to the Australian Army operating in Bougainville in July and August 1945 . The frigate carried Lieutenant General Kanda and Vice Admiral Baron Samejima , officers of the Japanese Imperial High Command to the surrender of Torokina on 8 September 1945 . She was also involved in the surrenders of Nauru on 13 September and Ocean Island on 1 October ; both ceremonies conducted on her quarterdeck . The ship was awarded the battle honour " Pacific 1945 " for her wartime service . " Diamantina " returned to Sydney , arriving at Garden Island on 13 December 1945 with 86 passengers embarked . The ship remained in Sydney until 1 February 1946 , when she departed for a patrol in New Guinea waters . " Diamantina " returned to Sydney on 14 June , and was paid off into reserve on 9 August 1946 . 1959 - 1980 . " Diamantina " was recommissioned as an oceanographic survey ship on 22 June 1959 . She carried the pennant numbers F377 , A266 , and GOR266 at various points throughout this period of her career . After successfully completing her first oceanographic survey in July , she embarked on her first oceanographic cruise on 20 August . On 20 September , the ship performed the first survey of the Montebello Islands following the British atomic test , Operation Hurricane . On 22 October , " Diamantina " carried out the first survey of the waters around Christmas Island . " Diamantina " ’ s most notable achievement during her second commission was the discovery of the deepest known part of the Indian Ocean on 7 February 1960 , which was named Diamantina Deep after the ship . Based in Fremantle , Western Australia , " Diamantina " remained in service as an oceanographic vessel until 1980 . Decommissioning and preservation . " Diamantina " paid off from the RAN on 29 February 1980 , and was the last World War II - era frigate to serve Australia . " Diamantina " was handed over to the Queensland Maritime Museum where she is permanently berthed in the dry dock located on the Brisbane River at South Brisbane . In March 2006 , " Diamantina " was towed out into the river to allow repairs to the dock , which had been flooded since the seals failed in 1998 . As of July 2006 , she has been returned to the dry dock adjacent to the Queensland Maritime Museum , where she is used as a self - touring museum ship . During the 2010 – 2011 Queensland floods , the dry dock flooded .