In a desperate attempt to remedy the shortage of aircraft-carriers, the Japanese naval staff decided that certain large fleet auxiliaries such as submarine tenders should be designed for rapid conversion to carriers in wartime. One such class was the 'Tsurigizaki' class of high-speed oilers, which were ordered under the 1934 Second Reinforcement Programme; their hulls were specially strengthened. The design was then altered to submarine tenders, and the lead-ship entered service in that role early in 1939. Her sister ship Takasaki, however, was not completed, and was laid up in the shipyard for nearly four years. Work on her conversion to a carrier started in January 1940, under the new name Zuiho.
Apart from the replacement of the unreliable diesels with geared steam turbines, as much of the original hull was retained as possible. A single hangar was provided, accommodating a maximum of 30 aircraft, with two centreline lifts; there were two catapults but no island superstructure. To retain the high speed and endurance all planned armouring was deleted. The conversion was carried out in a year, and the Zuiho joined the Combined Fleet in January 1941. With the old Hosho (Carrier Division 3) she was sent to the Palaus in the late autumn of that year and took part in the attack on the Philippines. She then returned to Japan for repairs before taking part in the conquest of the East Indies in the spring.
Luckily for the carrier, she was with the Support Force at Midway, and escaped the destruction of the main carrier force. In the Battle of the Santa Cruz Islands she was part of Admiral Nagumo's Carrier Strike Force. At 07.40 on 25 October 1942 a divebomber from the USS Enterprise made a surprise attack out of low cloud, dropping its bomb in the centre of the flight deck. With a 50-ft (15-m) crater in her flight deck the Zuiho could no longer operate aircraft, and so after launching her aircraft the Zuiho returned to base.
In February 1944 Zuiho rejoined Carrier Division 3, and she took part in the Battle of the Philippine Sea, when her aircraft scored a hit on the battleship South Dakota. In the fighting around Leyte Gulf she was one of the doomed carriers which attempted to decoy the Americans: in the Battle of Cape Engano she was hit by two bombs on the flight deck and was near-missed six times. In spite of a serious fire and flooding she was under way for another 6 hours, as the other carriers were picked off. Finally it was her turn, and three waves of attackers finished her off.
Specification Zuiho Displacement: 11,262 tons standard, 14,200 tons full load Dimensions: length 204.8 m (672 ft 0 in) overall; beam 18.2 m (59 ft 8 in); draught 6.6 m (21 ft 8 in) Machinery: 2-shaft geared steam turbines delivering 52,000 shp (38770 kW) Speed: 28,2 knots Armour: none Armament: four twin 127-mm (5-in) dual-purpose and four twin 25-mm AA guns Aircraft: 30 Complement: 785 officers and men