Battle of convoy ON-127, in the middle of the North Atlantic 800 miles West of Ireland. At 00.16 AM, U-404 damages Norwegian tanker SS Marit II which continues to USA with the convoy (2 killed). At 1.35 AM, U-218 blows a 30 foot hole in Norwegian tanker MV Fjordaas which is able to return to the Clyde, Scotland, arriving on September 15 (no casualties). At 11.50 AM, U-96 sinks 3-masted Portuguese fishing schooner Delães in the vicinity because U-96 “hears Asdic signals from the ship”. At 7.25 PM, U-584 sinks Norwegian MV Hindanger (1 killed, 40 survivors picked up by Canadian corvette HMCS Amherst).
250 miles South of the Azores, Kapitänleutnant Rolf Mützelburg allows the crew of U-203 to swim in the sea but he dies when he dives off the conning tower and hits the ballast tank (saddle tank) below the waterline.
At 1 PM in the Gulf of St. Lawrence, within sight of onlookers on Cap-Chat, U-517 sinks Canadian corvette HMCS Charlottetown (9 killed, 55 survivors picked up by minesweeper HMCS Clayoquot).
Aleutian Islands. The US airfield Adak Island is completed and begins bombing raids against Japanese-held Kiska Island, 250 miles West.
Allied/Japanese diplomatic personnel exchanges at Lourenço Marques, Portuguese East Africa (now Maputo, Mozambique). Japanese liner Kamakura Maru leaves for Singapore with 870 Japanese diplomats while British SS El Nil returns to Britain with 400 diplomats (including the embassy staff from Tokyo).
In the Gulf of Bothnia near the Finnish Åland Islands, Soviet submarine S-13 sinks Finnish collier SS Hera and also sinks a lifeboat full of survivors. Another lifeboat escapes to one of the Åland Islands.
Battle of Edson’s Ridge, Guadalcanal. Based on intelligence from his raid at Taivu 3 days ago, US Marine Colonel Edson believes the Japanese attack will come from the South of Henderson Field and he places 840 troops to block their approach on Lunga Ridge (a low, narrow coral ridge with dominating views, 1 km long between 2 rivers). Japanese bombers attack Lunga Ridge during the day, confirming Edson’s hunch.
8 miles Northwest of Vakuta Island 120 miles North of Milne Bay, Papua, US B-17 and B-25 bombers sink Japanese destroyer Yayoi with a direct hit in the stern (68 killed, 83 survivors reach Normanby Island 75 miles South). The other destroyer Isokaze suffers minor damage due to near-misses and abandons the attempt to evacuate stranded troops from nearby Goodenough Island.
In the Makassar Strait between Borneo and Celebes, US submarine USS Saury is recharging batteries on the surface in the dark. At 9 PM, USS Saury spots and sinks Japanese auxiliary aircraft transport Kanto Maru with 3 torpedoes (39 killed).
In the evening in the Indian Ocean, German armed merchant cruiser Michel stops British MV Empire Dawn (in ballast to Trinidad from Durban, South Africa) with a barrage of shellfire that continues despite signals that the crew is abandoning ship (22 killed, 22 survivors taken prisoner on Michel).
At 10.37 PM, U-514 attacks ships in Bridgetown harbour, Barbados, sinking Canadian SS Cornwallis in shallow the waters. SS Cornwallis will be raised and repaired at Trinidad and Mobile, Alabama, returning to service in August 1943.