Chūichi Nagumo
On 21 August, the rest of the Japanese "Ka" naval force departed Truk, heading for the southern Solomons. These ships were basically divided into three groups. The "main body" contained the Japanese carriers and , the light carrier , and a screening force of one heavy cruiser and eight destroyers, commanded by Vice Admiral Chūichi Nagumo in "Shōkaku". The "vanguard force" consisted of two battleships, three heavy cruisers, one light cruiser, and six destroyers, commanded by Rear Admiral Hiroaki Abe. The "advanced force" contained five heavy cruisers, one light cruiser, six destroyers, and the seaplane carrier , commanded by Vice Admiral Nobutake Kondō. Finally, a force of about 100 IJN land-based bombers, fighters, and reconnaissance aircraft at Rabaul and nearby islands were positioned for operational support. Nagumo's main body positioned itself behind the "vanguard" and "advanced" forces in an attempt to more easily remain hidden from U.S. reconnaissance aircraft.