The Battle off Horaniu (Japanese: 第一次ベララベラ海戦) was a minor naval battle of the Pacific campaign of World War II, fought near Vella Lavella, in the Solomon Islands. On the night of 17–18 August 1943, four U.S. Navy destroyers intercepted an Imperial Japanese Navy convoy carrying troops to Horaniu, on the northern coast of Vella Lavella, where they were to establish a barge base to support the movement of troops through the region. The Japanese convoy was escorted by four destroyers, and both sides exchanged torpedoes and gunfire from long range. After two Japanese destroyers were slightly damaged, the escort withdrew, allowing the U.S. force to sink five small ships from the convoy. However, the majority of the troop carrying barges escaped by hiding along the Vella Lavella coast, and subsequently completed their mission on 19 August. In October, the Japanese used the base to support the mass withdrawal of troops from Kolombangara. Background In mid-1943, in the wake of the Guadalcanal campaign, the Allies launched their next offensive in the Solomon Islands, focused upon seizing the major Japanese airstrip at Munda on New Georgia Island. After the fall of Munda on 4–5 August, and defeat in the Battle of Vella Gulf on 6–7 August, the Japanese decided to evacuate their garrisons in the central Solomons, firstly moving to Baanga Island while planning to bring forces south from Rabaul for a potential counterattack. On 15 August, the Allies landed on Vella Lavella, bypassing the main Japanese troop concentration on Kolombangara. To maintain contact with these troops, and ensure their later withdrawal, the Japanese planned to establish a staging base at Horaniu, on the northern tip of Vella Lavella. Commanded by Rear Admiral Matsuji Ijuin, the destroyers , , , and left Rabaul on 17 August to rendezvous with a troop convoy from Buin, on Bougainville. This convoy included 13 barges, four motor torpedo boats, the subchasers Cha-12 and Cha-5, and a Soukoutei-class armored boat. The troops embarked consisted of two Imperial Japanese Army companies and an Imperial Japanese Navy platoon. Battle After the Japanese force was located by Allied reconnaissance aircraft, Admiral Theodore S. Wilkinson, commander of the Third Amphibious Force, dispatched a division of four destroyers from Purvis Bay on Florida Island to intercept them. This force consisted of , , , and , under Captain Thomas J. Ryan. They departed their anchorage at 15:27 on 17 August and began