A Citation in the London Gazette, 16th December, 1944, gives the following details:

"On 24th May, 1941, while off the coast of Sicily, Lieutenant-Commander Wanklyn, in command of H.M. Submarine Upholder, sighted an enemy troop convoy escorted by destroyers. Observation by periscope could not be relied on, owing to failing light, and a surface attack would have been easily seen. Upholder's listening gear was out of action. Despite these difficulties, Lieutenant-Commander Wanklyn, though aware of the risk of being rammed by the escorting destroyers, pressed home his attack and sank a large troopship. The destroyers at once counter-attacked, and dropped thirty-seven depthcharges. With great courage, coolness and skill, and without listening gear, Lieutenant-Commander Wanklyn brought Upholder clear and back to harbour. Before this outstanding attack and since being made a Companion of the Distinguished Service Order, Lieutenant-Commander Wanklyn had torpedoed a tanker and a merchant vessel. He continued to show the utmost courage in the face of the enemy, and carried out attacks on enemy vessels with skill and relentless determination, sinking one destroyer, one U-boat, two troop transports, one tanker and three supply ships. He also probably destroyed, by torpedoes, one cruiser and one destroyer, and probably hit another cruiser."The Citation in the London Gazette of 16th December, 1944, gives the following details: On 24th May, 1941, while off the coast of Sicily, Lieutenant-Commander Wanklyn, in command of H.M. Submarine Upholder, sighted an enemy troop convoy escorted by destroyers. Observation by periscope could not be relied on, owing to failing light, and a surface attack would have been easily seen. Upholder's listening gear was out of action. Despite these difficulties, Lieutenant-Commander Wanklyn, though aware of the risk of being rammed by the escorting destroyers, pressed home his attack and sank a large troopship. The destroyers at once counter-attacked, and dropped thirty-seven depthcharges. With great courage, coolness and skill, and without listening gear, Lieutenant-Commander Wanklyn brought Upholder clear and back to harbour. Before this outstanding attack and since being made a Companion of the Distinguished Service Order, Lieutenant-Commander Wanklyn had torpedoed a tanker and a merchant vessel. He continued to show the utmost courage in the face of the enemy, and carried out attacks on enemy vessels with skill and relentless determination, sinking one destroyer, one U-boat, two troop transports, one tanker and three supply ships. He also probably destroyed, by torpedoes, one cruiser and one destroyer, and probably hit another cruiser.