Operation Pedestal. In the Mediterranean, Italian and German aircraft and submarines converge on the Malta supply convoy. British aircraft carrier HMS Furious flies off 37 Spitfires to Malta, then turns back for Gibraltar. At 1.15 PM 70 miles South of Cape Salinas, Majorca, U-73 hits British aircraft carrier HMS Eagle with 4 torpedoes, which sinks in 4 minutes with 16 Sea Hurricane fighters depriving Pedestal of much-needed air cover (160 killed, 927 survivors picked up by British destroyers HMS Laforey and HMS Lookout and tug HMS Jaunty). 4 Sea Hurricanes are airborne at the time and land on other carriers. At 8 PM, Italian fighters and bombers attack in force but do little damage.
Japanese Navy responds to American landings on Guadalcanal in the Solomon Islands. Battleship Mutsu, cruisers Atago, Takao, Maya, Haguro, Yura and Myoko, seaplane tender Chitose and 10 destroyers leave Tokyo Bay, Japan, for the naval base at Truk Lagoon. They will ferry in troops and supplies to Guadalcanal, 1200 miles South.
Case Blue. German 6th Army crosses the River Don and meets up with 4th Panzer Army which has been moving South of the Don, capturing the town of Kalach. Further South in the Caucasus, German 1st and 17th Armies race across the flat Kuban plain towards the Black Sea coast, threatening the Soviet port of Novorossisk. Soviet exodus of ships, naval troops and supplies out of Novorossisk continues and many vessels are scuttled to prevent capture by the Germans.
South Atlantic. At 2.27 PM 870 miles West of Freetown, Sierra Leone, U-130 sinks Norwegian SS Mirlo (all 37 crew abandon ship in 3 lifeboats, picked up by British sloop HMS Banff, destroyer HMS Boreas and armed trawler HMS Canna on August 18 - 20). At 7.13 PM 1050 miles West of Freetown, U-109 sinks British tanker SS Vimeira (7 killed, 37 survivors in 2 lifeboats picked up by British SS Sylvia de Larrinaga on August 12 and British corvette HMS Crocus on August 22).
Overnight, 154 RAF bombers (68 Wellingtons, 33 Lancasters, 28 Stirlings and 25 Halifaxes) raid Mainz, Germany, just across the Belgian border. The centre of Mainz is badly damaged (152 killed). 3 Wellingtons, 2 Halifaxes and 1 Lancaster are lost.