surface speed was 12 knots and submerged could reach nine. She could dive to periscope depth in 45 seconds. After a five-month fitting-out and sea trial phase she was declared battle ready. Wanklyn sailed for the Mediterranean Theatre on 10 December 1940. The vessel docked at Gibraltar before deploying for Malta. The entry of Italy into the war on 10 June 1940 had made the region a war zone. The Italian Navy (Regia Marina) and Italian Air Force (Regia Aeronautica) laid siege to the island. In September 1940 the Italian invasion of Egypt began a major land campaign. The objective of British submarine forces was to prevent the large Italian merchant fleets from supplying the Italian Army, and later the German Afrika Korps, in North Africa. Wanklyn now formed part of the 10th Submarine Flotilla in Malta under the command of Commander George Simpson. Upholder arrived there on 14 January 1941. While journeying to Malta, he provided distant cover for the supply fleet Operation Excess. Mediterranean Wanklyn's first success in this theatre was an attack on a large ship escorted by a destroyer heading to port in Tripoli. At 01:30 on 26 January 1941 he began his attack surfaced. He evaded the destroyer, but both torpedoes missed. Later another convoy was sighted and he fired two torpedoes but once again, both missed. On 28 January 1941 Wanklyn's lookouts sighted another convoy. Closing undetected to 900 yards, he scored one hit on the 7,500-ton transport Duisburg, which was damaged. On 30 January 1941 he fired two torpedoes at a northbound convoy and claimed a hit on a 5,000-ton cargo ship which has not been confirmed. Having expended all of his torpedoes, Upholder berthed in Malta on 1 February. He was promoted lieutenant commander on 1 February 1941. Wanklyn was back at sea on 12 February 1941. In the dark, lookouts sighted a submarine and Wanklyn ordered an attack. After realising it was a British vessel from its silhouette, the attack was aborted. It was later discovered the submarine had been the British T-class submarine . Ten days later, on 22 February, restrictions on British submarines were lifted and shipping in the entire Mediterranean Sea was considered fair game and to be sunk on sight. On 10 March, a convoy of small ships 'in ballast' was sighted off Tripoli. Conscious of the shortage of torpedoes he held fire. While on his fourth