Operation Catapult. British attack the brand new French battleship Richelieu in dock at Dakar, Senegal. Swordfish torpedo bombers from aircraft carrier HMS Hermes hit Richelieu, tearing a 40 foot hole and causing her to touch bottom, but Richelieu will be repaired in a few days. However, conflict is avoided at Alexandria, Egypt, where negotiations have been ongoing since July 3. Aware of the destruction wrought on the French ships at Mers-el-Kébir by superior British forces, French Admiral Godefroy agrees that his warships will remain in port to avoid being attacked or captured by British ships.
Overnight, British submarine HMS H43 lands Lieutenant Hubert Nicolle on Guernsey (he is originally from the island) to do reconnaissance on the German garrison, in preparation for a commando raid on the island, Operation Ambassador. http://www.independent.co.uk/arts-entertainment/obituary-hubert-nicolle-1175816.html
U-99 sinks British SS Sea Glory (all 29 crew lost). 23 hours later U-99 sinks Swedish SS Bissen (all 20 crew survive) 80 miles South of Cape Clear, Ireland. http://www.uboat.net/allies/merchants/ships/411.html
U-34 sinks Dutch tanker Lucrecia (carrying fuel oil) 100 miles West of Lands End, England (2 killed). 30 survivors are picked up by Portuguese steamer Alfarrarede. http://www.uboat.net/allies/merchants/ships/413.html