Battle of the Eastern Solomons

The naval Battle of the Eastern Solomons (also known as the Battle of the Stewart Islands and in Japanese sources as the Second Battle of the Solomon Sea) took place on 24–25 August 1942 and was the third carrier battle of the Pacific campaign of World War II and the second major engagement fought between the United States Navy and the Imperial Japanese Navy (IJN) during the Guadalcanal campaign. As at the Battle of the Coral Sea and the Battle of Midway, the ships of the two adversaries were never within sight of each other. Instead, all attacks were carried out by carrier-based or land-based aircraft.

After several damaging air attacks, the naval surface combatants from both America and Japan withdrew from the battle area. Although neither side secured a clear victory, the U.S. and its allies gained a tactical and strategic advantage. Japan's losses were greater and included dozens of aircraft and their experienced aircrews. Also, Japanese reinforcements intended for Guadalcanal were delayed and eventually delivered by warships rather than transport ships, giving the Allies more time to prepare for the Japanese counteroffensive and preventing the Japanese from landing heavy artillery, ammunition, and other supplies.

On 7 August, Allied forces, consisting mainly of U.S. Marine Corps units, landed on Guadalcanal, Tulagi, and the Florida Islands in the Solomon Islands. The landings on the islands were meant to deny their use by the Japanese as bases to threaten supply routes between the U.S. and Australia, and secure the islands as launching points for a campaign with an eventual goal of isolating the major Japanese base at Rabaul while also supporting the Allied New Guinea campaign. The landings initiated the six-month-long Guadalcanal campaign.

The Allied landings were directly supported by three U.S. aircraft carrier task forces (TFs): TF 11 centered around USS Saratoga; TF 16 based on USS Enterprise; and TF 18 formed around USS Wasp; their respective air groups; and supporting surface warships, including a battleship, four cruisers, and 11 destroyers. Not all of the ships were U.S. warships; attached to TF 18 was TF 44, commanded by Victor Alexander Charles Crutchley, which included the Royal Australian Navy cruisers HMAS Australia and Hobart. The overall commander of the three carrier task forces was Vice Admiral Frank Jack Fletcher, who flew his flag on Saratoga. The aircraft from the three carriers provided close air support for the invasion forces and defended against Japanese air attacks from Rabaul. After a successful landing, they remained in the South Pacific Area charged with four main objectives: guarding the line of communication between the major Allied bases at New Caledonia and Espiritu Santo; giving support to Allied ground forces at Guadalcanal and Tulagi against possible Japanese counteroffensives; covering the movement of supply ships aiding Guadalcanal; and engaging and destroying any Japanese warships that came within range.

Between 15 and 20 August, the U.S. carriers covered the delivery of fighter and bomber aircraft to the newly opened Henderson Field on Guadalcanal. This small, hard-won airfield was a critical point in the entire island chain, and both sides considered that control of the airbase offered potential control of the local airspace. In fact, Henderson Field and the aircraft based there were able to limit the movement of Japanese forces in the Solomon Islands and assist in the attrition of Japanese air forces in the South Pacific Area. Allied control of Henderson Field became the key factor in the entire battle for Guadalcanal.

Surprised by the Allied offensive in the Solomons, Japanese naval forces, commanded by Admiral Isoroku Yamamoto, and army forces prepared a counteroffensive, with the goal of driving the Allies from Guadalcanal and Tulagi. The counteroffensive was called "Operation Ka", from the first syllable in the Japanese name for Guadalcanal. The naval forces had the additional objective of destroying Allied warship forces in the South Pacific Area, specifically the U.S. carriers.

On 16 August, a Japanese convoy of three slow transport ships loaded with 1,411 soldiers from the 28th "Ichiki" Infantry Regiment, as well as several hundred naval troops from the 5th Yokosuka Special Naval Landing Force, departed the major Japanese base at Truk Lagoon (Chuuk) and headed towards Guadalcanal. The transports were guarded by the light cruiser Jintsū, eight destroyers, and four patrol boats, with the escort force commanded by Rear Admiral Raizō Tanaka, who flew his flag in Jintsū. Also departing from Rabaul to help protect the convoy was a "close cover force" of four heavy cruisers from the 8th Fleet, commanded by Vice Admiral Gunichi Mikawa. These were the same, relatively old, heavy cruisers that had defeated an Allied naval surface force in the earlier Battle of Savo Island, less Kako, which had been sunk by an American submarine on her journey from that battle to her base. The four heavy cruisers of Mikawa's group left the Shortlands on 23 August and became tangentially involved, dropping bombs on Henderson Field during the following nights with their float planes. Tanaka planned to land the troops from his convoy on Guadalcanal on 24 August.

On 21 August, the rest of the Japanese Ka naval force departed Truk, heading for the southern Solomons. These ships were divided into three groups. The "main body" contained the Japanese carriers Shōkaku and Zuikaku, the light carrier Ryūjō, 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, five destroyers, the seaplane carrier Chitose, and a "covering group" consisting of the battleship Mutsu and three destroyers, 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.