Japanese lead ship of Zuiho-class
 was the name ship of her class of two light aircraft carriers built for the Imperial Japanese Navy. Originally laid down as the submarine tender "Takasaki" (Japanese: 高崎, "Tall Cape"), she was renamed and converted while under construction into an aircraft carrier. The ship was completed during the first year of World War II and played a minor role in the Battle of Midway in mid-1942. She participated in the Guadalcanal Campaign during the rest of 1942. Significantly damaged during the Battle of the Santa Cruz Islands in that campaign, after repairs "Zuihō" covered the evacuation of Japanese forces from Guadalcanal in early 1943.
Her aircraft were disembarked several times in mid- to late-1943 and used from land bases in a series of battles in the Southwest Pacific. "Zuihō" participated in the Battles of the Philippine Sea and Leyte Gulf in mid-1944. In this last engagement, she mainly served as a decoy for the main striking forces and was sunk by American aircraft. In between battles, the ship served as an aircraft ferry and a training ship.
Design and conversion.
The submarine support ship "Takasaki" was laid down on 20 June 1935 at the Yokosuka Naval Arsenal and was designed to be converted to either a fleet oiler or a light aircraft carrier as needed. She was launched on 19 June 1936 and began a lengthy conversion into a carrier while fitting-out. The ship was renamed "Zuihō" during the process which was not completed until 27 December 1940 when she was commissioned.
After her conversion, "Zuihō" had a length of overall. She had a beam of and a draft of . She displaced at standard load. Her original diesel engines were intended to give her a top speed of , but they were replaced by a pair of geared steam turbine sets as part of her conversion. Each turbine set drove one propeller using steam provided by four water-tube boilers. The turbines produced a total of which gave "Zuihō" a maximum speed of . She carried enough fuel oil to give her a range of at a speed of . Her crew numbered 785 officers and men.
"Zuihō" was a flush-deck design and lacked an island superstructure. Her flight deck was long and had a maximum width of . The ship was built with a single hangar long and wide, intended to house 30 aircraft. The hangar was served by two octagonal centerline aircraft elevators. She had arresting gear with six cables, but was not fitted with an aircraft catapult. 
The ship's primary armament consisted of eight Type 89 dual-purpose guns in twin mounts on sponsons along the sides of the hull. "Zuihō" was also initially equipped with four twin Type 96 light anti-aircraft (AA) guns, also in sponsons along the sides of the hull. In 1943, her light AA armament was increased to forty-eight 25 mm guns. The following year, an additional twenty 25 mm guns were added in addition to six 28-round AA rocket launchers.
Service.
After commissioning, "Zuihō" remained in Japanese waters until late 1941. Captain Sueo Ōbayashi assumed command on 20 September and "Zuihō" became flagship of the Third Carrier Division ten days later. She was briefly assigned to the 11th Air Fleet in Formosa on 13 October and arrived in Takao the following day. The ship returned to Japan in early November, rejoining the Third Carrier Division, and was given a brief refit later in the month. Together with the carrier and six battleships, "Zuihō" covered the return of the ships of the 1st Air Fleet ("Kido Butai") as they returned from the attack on Pearl Harbor in mid-December.
In February 1942, the ship ferried Mitsubishi A6M "Zero" fighters to Davao City, Philippines for the 11th Air Fleet. Transferred to the First Fleet after the Third Carrier Division was disbanded on 1 April, "Zuihō" remained in Japanese waters until June when she participated in the Battle of Midway. She was assigned to the Main Body of the invasion force and her aircraft complement consisted of six Mitsubishi A5M "Claude" and six A6M2 "Zero" fighters, and twelve Nakajima B5N2 "Kate" torpedo bombers. After the initial American airstrikes that sank three Japanese carriers, the Main Body was ordered to rendezvous with the "Kido Butai" at high speed, but this order was cancelled later that evening. Late on 5 June, the fighters of her combat air patrol drove off an American Consolidated PBY Catalina reconnaissance aircraft of VP-44 that had spotted the Main Body. "Zuihō" was ordered the following afternoon to prepare to launch an airstrike, together with aircraft from the seaplane tender , on the carriers that the Japanese imagined were pursuing them, but this was cancelled on the morning of 7 June when it became clear that there was no pursuit. After a brief refit in July–August in Sasebo, the ship was assigned to the First Carrier Division with the carriers and on 12 August.
The division sailed to Truk on 1 October to support Japanese forces in the Guadalcanal Campaign and departed from Truk 10 days later based on the promise of the Imperial Japanese Army to capture Henderson Field on Guadalcanal. At this time, "Zuihō" carried eighteen A6Ms and six B5Ns. The Japanese and American carrier forces discovered each other in the early morning of 26 October at the opening of the Battle of the Santa Cruz Islands and each side launched airstrikes. The aircraft passed each other en route and nine of "Zuihō"'s Zeros attacked the aircraft launched by the aircraft carrier . They shot down three Grumman F4F Wildcat fighters and three Grumman TBF Avenger torpedo bombers and damaged one more of each type while losing four of their own. Two of "Enterprise"'s Douglas SBD Dauntless dive bombers operating as armed scouts hit "Zuihō" with bombs while the fleet was launching the first and second wave against the American carriers. This put her flight deck out of action, although she was not seriously damaged otherwise. Together with the damaged "Shōkaku", the ship withdrew from the battle and reached Truk two days later. After temporary repairs, the two carriers returned to Japan in early November and "Zuihō"'s repairs were completed on 16 December. In the meantime, Captain Bunjiro Yamaguchi assumed command.
The ship left Kure on 17 January 1943 and sailed for Truk with a load of aircraft. Upon arrival she was assigned to the Second Carrier Division with the carriers and "Zuikaku" to provide cover for the evacuation of Guadalcanal. "Zuihō"'s fighters were transferred to Wewak, New Guinea, in mid-February and then to Kavieng in early March, although the ship remained at Truk. They flew to Rabaul on mid-March to participate in Operation I-Go, a land-based aerial offensive against Allied bases in the Solomon Islands and New Guinea. The fighters returned to Truk on 18 March after claiming 18 Allied aircraft shot down. "Zuihō" arrived at Sasebo on 9 May and received a brief refit in mid-June. She returned to Truk on 15 July and remained in the area until 5 November when she returned to Yokosuka. Her air group, 18 Zeros and 8 D3As, was briefly deployed to Kavieng in late August – early September before returning to Truk. By this time, "Zuihō" was assigned to the First Carrier Division with "Shōkaku" and "Zuikaku" and they sailed for Eniwetok Atoll on 18 September for training; a secondary objective was to be in position to intercept any attacks by American carriers in the vicinity of Wake Island and the Marshall Islands area. That day the American carriers raided the Gilbert Islands and were gone by the time the Japanese reached Eniwetok on 20 September. Japanese intelligence reports pointed to another American attack in the Wake-Marshall Islands area in mid-October and Admiral Mineichi Koga sortied the Combined Fleet, including the First Carrier Division, on 17 October. They arrived at Eniwetok two days later and waited for reports of American activity until 23 October. They then sailed for Wake Island and then returned to Truk on 26 October without encountering any American ships.
"Zuihō"'s air group was transferred to Rabaul at the beginning of November, just in time to participate in the raid on Rabaul a few days later. The fighters claimed to have shot down 25 American aircraft at the cost of eight pilots; the survivors flew back to Truk and remained ashore. On 30 November, "Zuihō", together with the escort carriers and , departed Truk for Japan, escorted by four destroyers. The Americans had cracked the Japanese naval codes and positioned several submarines along their route to Yokosuka. unsuccessfully attacked "Zuihō" on 30 November, while torpedoed and sank "Chūyō" five days later with heavy loss of life. From December to May 1944, "Zuihō" ferried aircraft and supplies to Truk and Guam although she was reassigned to the Third Carrier Division on 29 January, together with the converted carriers and . Each of the three carriers was intended to be equipped with 21 fighters and 9 torpedo bombers, but this plan was changed on 15 February to a consolidated air group, the 653rd, that controlled the aircraft of all three carriers. While fully equipped with 18 Zero fighters, 45 Zero fighter-bombers, 18 B5Ns, and 9 Nakajima B6N "Jill" torpedo bombers by May, the air group's pilots were largely drawn from the two most recent classes of flight school graduates and lacked experience. The ship sailed for Tawi-Tawi on 11 May in the Philippines. The new base was closer to the oil wells in Borneo on which the Navy relied and also to the Palau and western Caroline Islands where the Japanese expected the next American attack. However, the location lacked an airfield on which to train the green pilots and American submarines were very active in the vicinity which restricted the ships to the anchorage.
Battle of the Philippine Sea.
The 1st Mobile Fleet was en route to Guimares Island in the central Philippines on 13 June, where they intended to practice carrier operations in an area better protected from submarines, when Vice Admiral Jisaburō Ozawa learned of the American attack on the Mariana Islands the previous day. Upon reaching Guimares, the fleet refueled and sortied into the Philippine Sea where they spotted Task Force 58 on 18 June. The Americans failed to locate Ozawa's ships that day and the Japanese turned south to maintain a constant distance between them and the American carriers as Ozawa had decided on launching his airstrikes early the following morning. He had deployed his forces in a "T"- shaped formation with the Third Carrier Division at the end of the stem, ahead of the First and Second Carrier Divisions that formed the crossbar of the "T". "Zuihō" and her consorts were intended to draw the attention of the Americans while the other carriers conducted their airstrikes without disruption.
Sixteen Aichi E13A floatplanes were launched by the heavy cruisers accompanying the carriers at 04:30 to search for the Americans; the three carriers launched a follow-up wave of 13 B5Ns at 05:20. The first wave spotted one group of four carriers from Task Force 58 at 07:34 and the Japanese carriers launched their aircraft an hour later. This consisted of 43 Zero fighter-bombers and 7 B6Ns, escorted by 14 A6M5 fighters; the carriers retained only 3 fighters, 2 fighter-bombers, 2 B6Ns and 2 B5Ns for self-defense and later searches. While the airstrike was still forming up, the second wave of searchers located Task Force 58's battleships and the airstrike was diverted to attack them. The Americans detected the incoming Japanese aircraft at 09:59 and had a total of 199 Grumman F6F Hellcat fighters in the air by the time the Japanese aircraft were in range of the American ships. The defending fighters decimated the Japanese aircraft and only 21 survived. The only damage inflicted was from one A6M2 that hit the battleship in her superstructure with a single bomb that wounded 50 crewmen, but did little other damage. Only 3 Hellcats were lost in the affair, 1 to a B6N, although the Japanese claimed four victories. Some of the surviving Japanese aircraft landed at Guam while others, including the 5 surviving B6Ns, returned to their carriers where they claimed one carrier definitely damaged and another probably hit.
At dusk, the Japanese turned away to the northwest to regroup and to refuel, while the Americans turned west to close the