Capt Sam Templeton leads B Coy 39th from Uberi to Ioribaiwa Ridge. Two soldiers unfit to continue left at Uberi.
Outside Rabaul, US sub S-37 sinks Japanese transport Tenzan Maru. Jap sub chaser Ch30 depth charges S-37 without success.
US Admiral Chester Nimitz issues orders for Marines to invade Solomon Islands, with objectives of Tulagi (Jap seaplane base) and Guadalcanal (where Japs are constructing airfield at Lunga Point).
Nimitz acts because Jap movements in Solomons threaten sea lanes from US to Australia.