Battle of Denmark Strait. At 5.52 AM, British battlecruiser HMS Hood and battleship HMS Prince of Wales open fire on German battleship Bismarck and cruiser Prinz Eugen from 24 km. Although they outgun the Germans, both British ships have flaws. At 6 AM, a 15 inch shell from Bismarck penetrates HMS Hood’s thin deck armour, exploding a magazine. Hood is blown in 2 and sinks quickly (1,415 killed, 3 survivors). HMS Prince of Wales (completed only 2 months earlier) is hit 7 times (13 killed) and retires at 6.04 AM with her new guns jammed. Bismarck is hit 3 times (no casualties) but flooding in her bows and a boiler room reduces speed to 28 knots. British cruisers HMS Suffolk and HMS Norfolk continue following Bismarck and Prinz Eugen but at 6 PM Prinz Eugen escapes South in a squall. At 11.50 PM, 8 Swordfish torpedo bombers from British aircraft carrier HMS Victorious attack Bismarck (1 torpedo hits with little damage, 1 killed).
Crete. In the face of constant flow of fresh German troops at Maleme and continued fighting around the airports at Rethimnon and Heraklion, Allies began a series of retreats South across Crete. German 55th Motor-Cycle Battalion, armed with Spandau machine guns mounted on side-cars, advances towards the South coast to prevent Allied reinforcements arriving from North Africa. Carpet-bombing by Luftwaffe levels the North coast town of Canae. Overnight, Minelayer HMS Abdiel transports 200 British commandos from Alexandria, Egypt, to Suda Bay, Crete. 800 more commandos are not landed at Port Lutro, Crete, due to bad weather.
10 miles off Sicily, British submarine HMS Upholder sinks Italian troopship SS Conte Rosso, carrying troops from Naples to Tripoli (1049 troops and crew killed, 1680 survivors).
Off the coast of West Africa, U-38 sinks British SS Vulcain at 2.49 AM (7 killed) and U-103 sinks Greek SS Marionga at 3.56 AM (26 dead, 5 crew escape on a raft).
850 miles off the coast of South Africa (now Namibia), German raider Atlantis shells British steamer Trafalgar (carrying 4500 tons of coal and 2 aircraft) and then sinks her with a torpedo when the 2 ships are on collision course (12 crew killed, 33 picked up from the water).