Operation Abercrombie. Overnight, Allied raiding party (100 British commandos of B and C troops No. 4 Commando and 50 Canadian infantry of 2nd Canadian Infantry Brigade, commanded by Major Lord Lovat) crosses the English Channel in motor torpedo boats and land near Boulogne, France, from the newly-designed new Landing Craft Support. They reconnoitre the beaches but fail to capture any German prisoners for interrogation or destroy a searchlight battery (1 British commando shot through the ankle by a German sentry).
After missing German ships on March 16, April 7 and April 14, Soviet submarine M-173 sinks German SS Blankenese in the Barents Sea 3 miles off the Northeast tip of Norway.
At 3.29 AM 375 miles southeast of Cape Hatteras, North Carolina, U-201 torpedoes US passenger/cargo ship SS San Jacinto carrying 79 crew and 104 passengers (5 crew, 9 passengers killed). 74 crew and 95 passengers (including 32 women and children) escape on 6 lifeboats and several rafts, before U-201 sinks SS San Jacinto with 75 rounds from the deck gun, and are picked up after dawn by US destroyer USS Rowan. U-201 then sinks British SS Derryheen on her maiden voyage at 9.05 AM (all 51 hands picked up by British MV Lobos and landed at Havana, Cuba).
Burma. Indian 17th Infantry Division has held Taungdwingyi since the Japanese attack on the Irrawaddy River line on April 11. With Japanese troops moving North all around them, Indian 17th Division withdraws 75 miles North to Mahlaing to protect Mandalay.
In the Mediterranean, German and Italian aircraft continue heavy bombing of Malta. 20 miles off the coast of Palestine, U-81 sinks 4 tiny sailing boats with shellfire from the deck gun including Egyptian El Saadiah at 4.45 AM and Aziza at 12.35 PM.
Overnight, RAF Bomber Command sends 64 Wellingtons and 5 Stirlings to Cologne, Germany, on an experimental raid to test the new Gee radio transmitter system for blind navigation at night. The raid is a partial success, with 12 to 15 aircraft dropping bombs accurately (44 high-explosive & 1200 incendiary bombs land in the city, 4 civilians killed, 8 wounded) but others miss by up to 10 miles. 2 Wellingtons are lost.