“No one knows the fallacy of chasing Japanese torpedo boats with cruisers better than I.”
— RAdm. Walden Lee “Pug” Ainsworth
During the week of 6 July, the U.S. had landed troops on New Georgia to attack Munda and had recently placed Marines on New Georgia’s northern shore to seize Bairoko.
RADM Walden Lee Ainsworth received orders to protect the north shore beachhead from attack by the “Tokyo Express” and attempt to prevent Japanese reinforcements from landing on Munda.
The American campaign to take Vila was not going as expected. Naval historian Samuel Eliot Morison called it the “most unintelligently waged land campaign of the Pacific war.” Japanese reinforcements could make a difference. A “Tokyo Express” was scheduled to sail for Vila on the night of July 12/13, 1943.
The “Tokyo Express” attempting to land re-enforcements was commanded by Rear Admiral Shunji Izaki. Assigned to Izaki was a support group of one light cruiser and five destroyers: light cruiser Jintsu (flagship for Izaki), destroyers Mikazuki, Yukikaze, Hamakaze, Kiyonami and Yugure. Also assigned was a transport group of four destroyers: Satsuki, Minazuki, Yunagi, and Matsukaze. The Japanese would attempt to land approximately 1500 troops at Vila.
Assigned to Ainsworth was the light cruisers USS Honolulu (flagship for Ainsworth), HMNZS Leander, and USS St. Louis; Destroyer Squadron 21 with Nicholas, O’Bannon, Taylor, Jenkins, and Radford; and Destroyer Squadron 12 with Ralph Talbot, Buchanan, Maury, Woodworth and Gwin. Destroyer Squadron 12 had been added to Ainsworth’s force, along with the Leander, to offset the losses his force had suffered in its frequent trips through “The Slot.”