The U.S. task force sailed from its base around Tulagi at 17:00 on 12 July, amidst clear skies and calm seas. Passing Savo Island, Ainsworth steered a course along the west coast of Santa Isabel Island, hoping to use it to hide his force from Japanese reconnaissance aircraft. His plan for the attack was to use the first squadron of five destroyers that formed his vanguard to fire torpedoes while his cruisers maneuvered into a position to use their main guns. After laying down a heavy barrage the cruisers would maneuver again to avoid return torpedoes from the Japanese destroyers. Having gone to general quarters due to concerns about being spotted in the bright moonlight of the clear night sky, around midnight the U.S task force altered course towards Visu Visu. They then increased their speed following reports from Allied reconnaissance aircraft that had spotted Isaki's force about away. Hamstrung by their slowest ship, "Leander", Ainsworth's task group was only able to make while Isaki's force was estimated to cruising at .