passage to Freetown. An oceanographic survey of the fishing grounds between Freetown and Agadir was completed. At Gibraltar in mid-November, she conducted trials of towed and free balloons carrying meteorological instruments before reaching Chatham for refit on 24 November 1967. She recommissioned on 30 January 1968 and in March undertook an oceanographic voyage designed to advance knowledge of air/sea interaction. She carried out surveys in the Bristol Channel in April and then, for six weeks, in the southern approaches to the River Clyde. For the following two months, she was based at Londonderry and an area in the north-western approaches to Ireland was surveyed to the line. At Chatham in late August, she took part in Navy Days and then visited the Pool of London in early September. The ship sailed Chatham in late October and carried out surveys off the west coast of Africa, spending Christmas 1968 in Gibraltar. In early January 1969 she carried out surveys off the French Mediterranean coast. She then took part in the Atlantic Trade Wind Experiment, with survey ships from West Germany and the US; this consisted of a 15-day drift, with engines stopped, from a position some west of Cape Verde Islands. Hydra returned to Sierra Leone in mid-February and carried out surveys until she sailed Freetown on 25 May 1969. She spent a fortnight investigating an up-welling off Cape Blanc, then calling at Gibraltar before arriving on 19 June 1969 for a refit at Chatham. A new ship's company joined at the end of August and she sailed from Chatham at the end of October for the Far East. Calls were made en route at Freetown, Simonstown and Mauritius and Singapore was reached in time for Christmas. A survey of the Malacca Strait was started on 31 December 1969. 1970s - and five years away from the UK Surveying a route wide down the length of the Malacca Strait was a mammoth task. Breaks for maintenance, fuel and recreation were taken at Singapore, with a longer interruption from mid-June to mid-October 1970 for refit by Sembawang Shipyard. The ship visited Port Swettenham before resuming surveys in the Malacca Strait. However, she was detached after a fortnight to support the British task force sent from Singapore to relieve the area of East Pakistan stricken by a severe cyclone and storm surge. The ship was used in a survey role, finding and marking