Overnight in the Bay of Biscay 250 miles West of France, U-502 is caught charging her batteries on the surface by an RAF Wellington that approaches using radar. The bomber illuminates U-502 with a high-powered spotlight (Leigh Light) and then sinks her with depth charges (all 52 hands lost). Use of the Leigh Light forces U-boats to start charging batteries during the day.
At 00.36 AM 90 miles East of the Azores, U-201 sinks British passenger/cargo ship SS Avila Star (84 killed, 112 escape in 4 lifeboats). 73 survivors in 3 lifeboats are picked up after 2 days by Portuguese destroyer Lima but 1 lifeboat with 39 aboard drifts until July 25, when 29 survivors are rescued by Portuguese sloop Pedro Nunes (1 dies aboard Pedro Nunes and 2 more die in hospital in Lisbon, Portugal).
At 5.26 AM in the Mediterranean 20 miles Southwest of Haifa, Palestine, U-375 sinks Norwegian SS Hero which disintegrates and sinks within 50 seconds (31 killed, 13 men on deck blown overboard and rescued by an escort ship).
At 5.21 AM 10 miles Southeast of Cap Chat, Quebec, Canada, U-132 (which arrived in the St. Lawrence River, on July 3) attacks convoy QS-15, sinking Belgian SS Hainaut (1 dead, 44 survivors) and Greek SS Anastassios Pateras (3 dead, 26 survivors). At 6.46 AM U-132 torpedoes British SS Dinaric which remains afloat on her cargo of timber until July 9 (4 killed). Canadian minesweeper HMCS Drummondville attempts to ram and drops depth charges, causing minor damage to U-132, before rescuing 28 crew and 6 gunners in a lifeboat from SS Dinaric.
U-boat and bomber attacks on Convoy PQ 17 continue. U-255 sinks American SS John Witherspoon (1 killed, 49 survivors float in lifeboats for 3 days in the freezing water) and American SS Pan Atlantic is sunk by the Luftwaffe.
Case Blue. 4th Panzer Army reaches the outskirts of Voronezh, despite counterattacks by of columns Soviet tanks which are thwarted by ferocious Luftwaffe bombing ahead of the Panzers. As General Paulus’ 6th Army reaches Ostrogozhsky, 70 miles South of Voronezh (clearly heading down the “Donets corridor” between the Donets and Don rivers), the German plan becomes apparent. Stalin realizes that the thrust is not towards Moscow but South into the oilfields of the Caucasus. He determines that Voronezh must be held, in order to control a vital North-South railway for moving troops into the Caucasus and also to prevent an encirclement of Timoshenko’s Southwest Front who will be allowed to withdraw East over the Don River.
At 4.15 PM, Japanese submarine I-10 sinks Greek merchant Nymphe in the Mozambique Channel.
At 6.37 PM in the Yucatan Channel 20 miles off the Yucatan Peninsula, U-154 sinks tiny Panamanian fishing boat MV Lalita with shellfire. At 6.57 PM in the Gulf of Mexico 45 miles South of Pascagoula, Mississippi, U-67 sinks Norwegian MV Bayard (11 killed, 21 survivors picked up by a Hall PH-2 flyingboat from US Coast Guard Air Station Biloxi).