HMS Cook ( K638 ) HMS " Cook " ( K638 / A307 ) was a Bay - class anti - aircraft frigate of the British Royal Navy , named for the explorer James Cook , which served as a survey ship , mostly in the Pacific Ocean from 1950 until 1964 . Construction . The ship was originally ordered from William Pickersgill & Sons Ltd . of South Bank , Middlesbrough , on 25 January 1943 as the " Loch Mochrum " . However the contract was then changed , and the ship was laid down as Admiralty Job Number 4813 on 30 November 1944 to a revised design as a Bay - class anti - aircraft frigate , and launched on 24 September 1945 as " Pegwell Bay " . After launching the contract was terminated and the ship was towed to HM Dockyard Devonport for conversion to a survey ship . Work began in February 1948 and was completed in July 1950 . No main armaments were fitted and changes were made to provide additional accommodation and offices for hydrographic work . More boats were fitted , together with Type 972 survey radar . The ship was renamed " Cook " and her pennant number changed to A307 . Service history . " Cook " was commissioned for sea trials at Devonport on 6 June 1950 and carried out local surveys before completing her complement from the survey ship in January 1951 . From then until December 1954 she was mainly employed in survey work off the west coast of Scotland , though she also sailed to the Gold Coast to survey there in mid - 1953 . In that year she also took part in the Fleet Review to celebrate the Coronation of Queen Elizabeth II . In 1955 " Cook " began to carry out trials of the Decca Two Range Survey System , which fixed the ship ' s position by radio signals from two shore stations . She recommenced survey operations in 1956 , with further radio trials and survey work in the Hebrides . In March 1957 she sailed to the Pacific , via the Azores , the West Indies , and Panama Canal , to observe the first British thermonuclear bomb test , code - named " Operation Grapple " , on 15 May . She then sailed to Fiji for survey work , which included gravimetric and magnetic measurements . In March 1958 , after refitting at Devonport Naval Base , Auckland , " Cook " sailed to the Solomon Islands , finding that the positions of some islands were incorrect . In August she sailed to Hong Kong to refit . In October 1958 , she sailed for New Britain , also surveying shoals and reefs east of the Philippines , and carrying out depth measurements of the Philippine Trench . The survey of the Solomon Islands continued from November 1958 to February 1959 , and further surveys were carried out around New Ireland . She arrived at Sydney in March to exchange Captain and surveying teams who had flown in from the UK . " Cook " returned to Fiji in May and in August to the Gilbert and Ellice Islands . She sailed to Singapore in November 1959 . After an inspection , the ship was received an extensive refit , receiving new and upgraded equipment , as well as improvements to her working and accommodation areas . In March 1961 she sailed to the New Hebrides , then returned to Fiji in July to continue survey work around the islands . She sailed to Auckland for repairs and annual inspection in September , then returned to Fiji in January 1962 . In May she sailed for the Gilbert Islands for surveys and soundings , then sailed for Singapore to refit in July . In October " Cook " returned to the Gilbert & Ellice Islands . After her annual inspection and repairs at Auckland in April – May 1963 , she returned to Fiji , surveying Bligh Water , and taking part in an international exploration project to examine equatorial currents in the central Pacific area . On 1 October 1963 " Cook " was grounded off Suva and badly holed forward . After ten hours she was refloated , and made temporary repairs at Suva . In November she sailed to Singapore where her Captain was court - martialed and found guilty of hazarding and stranding his ship . She then returned to the UK via the Indian Ocean , the Suez Canal , Malta and Gibraltar . On her arrival back in home waters on 24 February 1964 she flew the flag of the Hydrographer of the Navy as she sailed into Devonport . " Cook " was withdrawn from service and decommissioned on 1 May 1964 , and then put into Reserve . She was put on the Disposal List , and in 1968 was sold to British Iron & Steel Corporation ( BISCO ) for demolition . In April that year she was towed to Zeebrugge for breaking - up .