Ironbottom Sound
As darkness overspread the body of water known as Ironbottom Sound, several tropical rain storms and squalls began to cross the area, limiting visibility for both the Americans and the Japanese as they steamed towards each other, however several American ships were equipped with long range radar systems which began to detect the approaching Japanese ships at approximately 00:30hrs (12:30am). Consisting of two battleships, one cruiser and eleven destroyers, the Japanese fleet rounded the northwestern coast of Savo Island and entered Ironbottom Sound at approximately 01:10hrs (1:10am) and shaped their course for Henderson Field; the American airbase they were sent to destroy. Steaming through a heavy rain squall, the Japanese ships were totally unaware of the presence of the American force directly ahead of them, and the heavy rain prevented the US fleet from sighting the Japanese ships for over an hour after the first radar contact.