another in the returning strike. This was the first time a Japanese carrier force had faced a concerted air attack. Loss of Hermes Hermes and Vampire were away when Trincomalee was attacked. At 09:00 they reversed course. Shortly after the end of the attack on Trincomalee, an aircraft from Haruna spotted the ships. 80 Aichi D3A "Val" bombers, held in reserve on the Japanese carriers, attacked starting at 10:35. Both were sunk before noon near Batticaloa. Hermes was lost with 307 men after being hit by over forty bombs. Vampire was lost with 8 men. The nearby hospital ship Vita rescued 600 men. The Japanese attack expanded to nearby ships. The corvette was hit by aircraft from Soryu and sunk with 53 men. Also sunk were the naval auxiliary Athelstone, the tanker British Sergeant, and the cargo ship Norviken. British land-based Fulmars arrived only after Hermes was sunk. Two Fulmars and four Vals were destroyed. Nagumo disengaged after recovering the strike on Hermes. Aftermath British reaction The Japanese inflicted disproportionate damage on the enemy. They damaged port facilities, sank one carrier and two cruisers, destroyed a third of enemy ground-based fighters and nearly all of the enemy ground-based strike aircraft. In addition, 23 merchant ships, totalling 112,312 tons, were sunk, including those by the separate Japanese Malay Force. In return, the Japanese lost only 18 aircraft, with damage to about 31 more. Conversely, they failed to destroy, or even locate, the main bulk of the British Eastern Fleet. The British interpreted their position as precarious. Ceylon and the Eastern Fleet were required to safeguard the sea lines of communications through the Indian Ocean. The British expected the Japanese to continue threatening these lines. SIGINT suggested that the Japanese were preparing a deliberate advance across the Indian Ocean. The raid demonstrated that the RAF was too weak to defend Ceylon and the naval anchorages, and that the navy was ill-prepared to meet a Japanese carrier force. The Eastern Fleet transferred its main base to Kilindini, Kenya, in East Africa, temporarily ceding the eastern Indian Ocean to the Japanese; from there it continued contesting control of the central Indian Ocean on better terms. Force A, including its two aircraft carriers, Indomitable and Formidable, retired to Bombay, and Somerville regularly deployed a fast carrier force to the central Indian Ocean over the next six months, during which he operated from or near Ceylon