20 May 1943

UNITED KINGDOM: Due to incorrect operation of her Otway log (speed measuring device) submarine HMS Untamed begins to flood and settles in 160 feet of water off Sanda Island on the West coast of Scotland. Due to delays in escape attempts, and incorrect flood valve assembly, none are able to escape and the entire 36 man crew are poisoned by CO2. Untamed was eventually raised and recommissioned as HMS Vitality, finally being broken up in March 1946. (Alex Gordon)(108)

Frigates HMS Gardiner, Goodall, Goodson and Gore laid down.

Destroyer HMS St James laid down.

Boom defense vessel HMS Bartizan launched.

Minesweepers HMS Florizel and Foam launched.

Escort carrier HMS Nairana launched.

Frigate HMS Tees launched.

U-985, U-986 launched.

U-313, U-979 commissioned.

U-1023, U-1024 laid down.

MEDITERRANEAN SEA: The full weight of Allied air power is being thrown at airfields in Italy, Sicily and Sardinia in an attempt to neutralize the Luftwaffe and the Italian air force. Over the past 48 hours, at least 186 Axis aircraft have been destroyed in day and night bombing. The most spectacular raid hit Grosseto airfield, 90 miles north of Rome. Flying Fortresses saturated the field and installations with fragmentation bombs, leaving 58 Italian bombers wrecked.

Minesweeper HMS Fantome is mined during clearance operations off Cape Bon and has her stern blown off. She is towed back to Bizerta, but found to be beyond repair and paid off as a constructive loss. There is one casualty but 36 survive. (Alex Gordon)(108)

INDIAN OCEAN: The Benakat left Capetown in a coastal convoy which was formed in the Table Bay, but left after three days to continue her voyage on the prescribed route to the destination. On 14 May the Admiralty radioed a new course. At 0728 on 20 May a torpedo struck her from U-197 on the starboard side, just before the bridge. The explosion caused very heavy damage, wrecked the starboard lifeboat and destroyed the starboard machinegun-platform, injuring the first and fourth mate (not seriously). After the hit no electric power was left, so the distress signal could only be send a few times. The ship began to list to starboard, and with some difficulty the crew succeeded in boarding the three remaining lifeboats and rowed away. About 20 minutes later a second torpedo hit the Benakat on the starboard side and broke her in two. The bow section sank and the stern remained afloat. The U-boat surfaced and fired with the deck gun at the port side of the vessel until the stern sank.

JAPAN: Tokyo: The Army General Staff issues orders for the withdrawal of all forces on Attu and Kiska Islands.

CANADA: Destroyer HMCS Columbia completed refit Saint John, New Brunswick and assigned to Western Local Escort Force.

U.S.A.: The US Tenth Fleet was established, headquartered in Washington, D.C., under command of Adm. Ernest J. King. The role of Tenth Fleet was to coordinate American anti-submarine operations in Atlantic. Rear Admiral Francis S. Low, King's Assistant Chief of Staff (Anti-submarine), was appointed Chief of Staff Tenth Fleet. All anti-submarine resources from US Fleet headquarters were transferred intact to the Commander Tenth Fleet. Admiral King retained command in order to direct asset allocation between commands in the Atlantic. He also did this to take the lead in the struggle with the US Army Air Corps over control of squadrons assigned to anti-submarine duty. General George C. Marshall wished Army very long-range and long-range squadrons to be commanded by an army general officer and to create a Coastal Air Command under the command of the Army Air Corps, headed by Lieutenant General McNarney. King was adamantly opposed to this arrangement and carried on an active struggle to gain control over long-range, land-based aircraft for naval uses. Eventually, the US Army Air Corps withdrew from anti-submarine patrols and transferred its aircraft to the USN. By Nov 43, the transfer of aircraft had been completed and all anti-submarine operations were the exclusive responsibility of Tenth Fleet. Rear-Admiral A.R. McCann relieved Admiral Low as Chief of Staff in Jan 45. Admiral King retained command of Tenth Fleet until it was dissolved on 15 Jun 45.

Frigate USS Annapolis laid down.

Destroyer escorts USS Barber and Greiner launched.

Frigate USS Belfast launched.

ATLANTIC OCEAN: U-258 sunk in the North Atlantic, in position 55.18N, 27.49W, by depth charges from an RAF 120 Sqn Liberator. 49 dead (all hands lost).