channels for small craft to take in food and supplies. She later resumed the Malacca Strait survey and spent Christmas 1970 at Singapore. During her year in the Malacca Strait, 63 shoal soundings were reported and promulgated by Notice to Mariners. The surveys of the Malacca Strait were concluded in March 1971 and she then spent three weeks in Hong Kong charting waters to the south of Lantao. On 6 April 1971, HMS Hydra sailed from Hong Kong to return to the UK, via the Panama Canal. She called at Yokosuka, Long Beach, Acapulco and Bridgetown, Barbados, making gravity, magnetics and bathymetric observations on passage and investigating several shoals. The summer and autumn of 1971 were spent at Chatham, with a refit and trials. Recommissioned at Chatham on 11 October 1971, she sailed on 30 November 1971 via the Cape of Good Hope, to return to the Far East from where she was not to return for five years, carrying out extensive surveys in the south Pacific. She left Simonstown on 3 January 1972 and called at Mauritius before carrying out a short investigation around the Aldabra Islands. After a visit to Mombasa to calibrate the ship's gravimeter, the first half of February was spent in the Seychelles where the ship's helicopter helped with the erection of Hi-Fix sites. Hydra was detached from surveying, and ordered to return to the Mauritius area, arriving off Rodrigues Island, one of the Mascarene Islands, on 26 February to assist in disaster relief. She left the area and arrived Singapore on 13 March, thus completing a circumnavigation of the globe in one year. After a short period of maintenance, she set sail for her 1972 survey area in the Solomon Islands. This survey, from 17 April to 18 August, covered the Bougainville Strait, last surveyed in 1884. Visits were paid to Honiara (Guadalcanal Island), Ghizo Island and Kieta (Bougainville Island). A three-week visit to Brisbane was brought forward in order to have two defective main engines replaced by two flown out from the United Kingdom. The ship arrived in Hong Kong at the end of August, where she spent three months, some time being spent on surveys in local waters. She sailed from Hong Kong on 28 October and arrived in Singapore for her annual refit which began on 13 November; the most important work was the installation of the SRN9 satellite navigation system.