HMS TETRARCH (Lt Cdr G H Greenaway) had deployed to the Mediterranean soon after building. She was due to return to the UK at the end of 1941 prior to undergoing a refit in the Unites States. She left Alexandria on 17 October 1941 loaded with fuel, stores and personnel for Malta, where she arrived a week later. She stayed in Malta for 2 days and sailed on 26 October for Gibraltar. The following day she communicated with HMS P34 whilst passing Sicily. That was the last communication received from TETRARCH. On 2 November 1941 she was reported late, presumed missing, at Gibraltar.