The American Fleet
The Japanese Fleet
Build-up to the Battle
Aftermath and Conclusion
The Battle of the Philippine Sea or 'Great Marianas Turkey Shoot (19-20 June 1944) was the first major naval battle in the Pacific since 1942 and was a crushing American victory that permanently destroyed Japanese naval aviation, leaving their carriers as hollow shells for the rest of the war.
The battle was a direct result of the Japanese 'A-Go' plan. At the heart of the Japanese Navy's hopes for victory was the idea of the 'decisive battle', in which the American fleet would be lured close to Japanese bases, worn down by land based aircraft and then destroyed by the Japanese Combined Fleet. Admiral Mineichi Koga, who replaced Admiral Yamamoto as commander of the Combined Fleet, had produced 'Operation Z', which called for a battle somewhere in the Philippines Sea. Koga was killed in a crash over the Philippines at the end of March 1944, and was replaced by Admiral Soemu Toyoda.
Toyoda and his new chief of staff Admiral Ryunosuke Kusaka, came up with a similar plan, the 'A-Go' plan. Once again the decisive battle was to be fought in the Philippine Sea, east of the Philippines. The ideal location would be somewhere near the Palau Islands or in the western Caroline Islands around Yap. This would reduce the amount of fuel needed by the Combined Fleet, and would also allow land based aircraft to play a major part in the battle. The Japanese had around 1,700 land-based aircraft available, with some 500 based on the Marianas. They came under the control of Vice-Admiral K. Kukuda, who was based on Tinian.
If the Americans moved against the Mariana Islands then they would have to be lured further west. The Japanese fleet would be split in two. The first part would sail openly into the area east of the Philippines in the hope that the Americans would advance to attack it. The second, and larger, part of the fleet, would move secretly through the Philippines and be ready to ambush the Americans.
The attack itself would be carried out by the First Mobile Fleet, under Admiral Jisaburo Ozawa. When Toyoda took office this fleet was based at Singapore, but Kusaka ordered it to move to Tawi Tawi, at the south-western corner of the Philippines. If more time had been available it might have moved further forward to the centre Philippines.
In the meantime the Japanese had to respond to the American invasion of Biak Island, off the north-western coast of New Guinea. The Americans invaded Biak at the end of May 1944, and the Japanese decided to try and get reinforcements to the island. The first two attempts failed and so Admiral Ugaki was dispatched to try and make a third attempt. He took the super battleships Yamato and Musashi and six cruisers.
The invasion of Biak was also seen by some in the Japanese command as the opportunity to carry out 'A-Go', in the hope that the US Pacific Fleet would be drawn to the island by a successful Japanese counterattack.
What the Japanese hadn't realised was that the Americans were now carrying out two separate advances across the Pacific. General MacArthur was moving west along New Guinea in preparation for his return to the Philippines, while in the Central Pacific Nimitz was leading the island hopping campaign. The Marshall Islands had been captured in January-February 1944 and the next target was the Mariana Islands. The Japanese confusion wasn't helped by the mobility of the fast carrier force, which hit Palau, Yap and Woleai in late March, then supported MacArthur's invasion of Hollandia on New Guinea, before hitting Truk on the way back north.
Both sides realised that the Mariana Islands were of vital importance. The Americans saw them as bases from where the very long range B-29 Superfortress could reach Japan. Guam had also been an American possession before the Japanese conquest. For the Japanese the islands guarded the already weak air links between Japan and New Guinea
The American Fleet
The overall American naval effort was commanded by Admiral Spruance, commander of the Fifth Fleet. Most of the fighting was carried out by Admiral Marc Mitscher's Task Force 58, the fast carrier task force.
The scale of the US Navy's expansion is clearly demonstrated by the size and power of Admiral Mitscher's Task Force 58. He had fifteen aircraft carriers at his disposal, split into four task groups (TG 58.1 to TG 58.4), each with a powerful escort. He also created a dedicated battleship force during the campaign (TG 58.7).
Mitscher's carrier force was made up of six new Essex class carriers, the veteran USS Enterprise and eight Independence class light carriers (roughly the equivalent of three or four fleet carriers).
This was all on top of the fleet that was escorting the invasion forces. This contained seven battleships, twelve escort carriers, eleven cruisers and ninety-one destroyers and destroyer-escorts.
Task Force 58 (Mitscher)
Task Group 58.1 (Rear-Admiral J. J. Clark)
Carriers: Hornet (CV-12), Yorktown (CV-10), Belleau Wood (CVL-24), Bataan (CVL-29)
Task Group 58.2 (Rear-Admiral A. E. Montgomery)
Carriers: Bunker Hill (CV-17), Wasp (CV-18), Monterey (CVL-26), Cabot (CVL-28)
Task Group 58.3 (Rear-Admiral J. W. Reeves, Jr)
Carriers: Enterprise(CV-5), Lexington (CV-16), Princeton (CVL-23), San Jacinto (CVL-30)
Task Group 58.4 (Rear-Admiral W. K. Harrill)
Carriers: Essex (CV-9), Langley (CVL-27), Cowpens (CVL-25)
Task Group 58.7 (Vice-Admiral W. A. Lee)
Task Group 58.7 was formed just before the battle, using two battleships from TG58.2 and five from TG 58.3, supported by four heavy cruisers and thirteen destroyers from the support fleet. One carrier group had to be allocated to guard the battleships. At its core were the battleships Washington, North Carolina, Iowa, New Jersey, South Dakota, Indiana and Alabama.
The Japanese Fleet
Although the Japanese had nine carriers available to them, only three of these were fleet carrier (Taiho, Zuihaku and Shokaku). Zuiho, Hiyo, Junyo, Ryuho, Chitose and Chiyoda were all light carriers produced by converted deliberately strongly built auxiliary warships or liners into carriers (Junyo and Hiyo were slightly larger than the other conversions and are sometimes seen as fleet carriers, but they carried fewer aircraft than the three full fleet carriers).
The Japanese also had the battleships Yamato, Musashi, Haruna, Kongo and Nagata.
The ships for the battle came from two sources. Most came from the First Mobile Fleet (Admiral Jisaburo Ozawa), which had just moved forward from Singapore to Tawi Tawi in the south-western corner of the Philippines. The remaining ships were made up of Admiral Ugaki's Japanese Southern Force, which came from Batjan, after being ordered to abandon the attempt to get reinforcements to Biak.
Once the two parts of the fleet had united, Ozawa split his force into three. Force A contained the fleet carriers Taiho, Zuihaku and Shokaku and was under his personal command. Force A contained 207 of the total of 430 available carrier aircraft. It was protected by three cruisers and seven destroyers.
Force B, under Rear-Admiral T. Joshima, contained the light fleet carriers Junyo and Hiyo and the light carrier Ryuho. It carried 135 aircraft and was protected by one battleship, one cruiser and nine destroyers.
Force C, under Vice-Admiral Kurita, contained the light carriers Chitose, Chiyoda and Zuiho. They carried 88 aircraft, and were protected by four battleships, five cruisers and eight destroyers.
Ozawa had 222 fighters and around 200 dive bombers and torpedo bombers. Many of the most experienced crews had been lost in the battles of 1942 and so his aircraft were flown by newly trained crews. Their only real advantage was their superior range, which meant that the Japanese could launch their attack from a position outside the range of an American attack. In theory they would also be able to use the airfields on Guam to rearm and refuel, but by the time they made their attack these airfields had been knocked out.
Build-up to the Battle
The Americans assembled two invasion forces for the Marianas. The Northern Attack Force (Vice-Admiral Richmond Turner) consisted of 71,000 men and was formed up at Hawaii. It was to attack Saipan. The Southern Attack Force (Rear Admiral R.L. Conolly) was 56,500 strong and was coming from Guadalcanal and Tulagi. It was to attack Guam. Saipan was to be attacked on 15 June, Guam when the moment was right.
The two invasion fleets were the first to move. On 8 June the Northern Attack Force reached Eniwetok and the Southern Attack Force reached Kwajalein. They then set off for the Marianas, protected by the powerful escort fleet (seven battleships, twelve escort carriers, eleven cruisers, ninety one destroyers and destroyer escorts).
Task Force 58 entered the battle on 11 June when 208 Hellcats carried out a fighter sweep over the Marianas to gain air superiority.
On 12 June one carrier task group attacked Guam, while the other three focused on Saipan and Tinian. That evening the fleet split. TG 58.1 and TG 58.4 were sent north to attack Chichi Jima and Iwo Jima in order to make sure that the Japanese couldn't use those bases to fly reinforcements down from Japan. The other two groups remained in the Marianas, where they continued to win control of the air.
On 13 June the Japanese realised that the Americans were almost certainly about to invade the Marianas, and Admiral Toyoda issued the orders to prepare for Operation A-Go.
The same day saw the Americans complete the destruction of Japanese air power in the Marianas. Most of the 500 aircraft based on the islands had been destroyed, but this vital information didn't reach Admiral Ozawa, who believed that he could still count on around 100 land based aircraft. That evening the fleet's battleships began a heavy bombardment of the shore defences.
On 15 June the troops from the Northern Attack Force invaded Saipan. This was the signal that the Japanese had been waiting for, and Admiral Toyoda ordered 'A-Go' to begin. Admiral Ugaki's detachment was ordered to abandon the attempt to reinforce Biak and instead move north to join up with the Mobile Fleet east of the Philippines. The Mobile Fleet had already moved forward and was between Negros and Panay when the orders arrived.
The Americans received a warning of the Japanese attack when the submarine USS Flying Fish spotted Ozawa's fleet leaving the San Bernardino Strait late on 15 June. Further south the submarine Seahorse spotted Admiral Ugaki's battleships.
On 16 June TG 58.1 and TG 58.4 carried out their attack on Iwo Jima and Chichi Jima. They then turned back south and headed for a fleet rendezvous on 18 June.
At 17.00 on 16 June the two parts of the Japanese fleet rendezvoused about a third of the way between the Philippines and the Marianas, and prepared to take on fuel. This took most of 17 June.
On 17 June the Japanese were spotted again, this time by the submarine USS Cavalla, which found them 800 miles west-southwest of Saipan. Admiral Spruance responded by ordering his troop transports to move east out of danger, while TF 58 was moved into the waters west of Tinian to guard against any Japanese attack. Although the American commanders would have liked to have dashed west to try and catch the Japanese carriers, their main role was to protect the landings on Saipan, so they had to stay close to the island. As the Japanese approached Spruance decided to group seven battleships into a dedicated 'Battle Line' - TG 58.7, to guard against any dash by the Japanese battleships.
By 10.30am on 18 June the five task groups of Task Force 58 had come back together west of Saipan. The battleships were posted to the west of the main line of carriers, with TG 58.4 posted to the north to guard the battleships. By 12 noon the American fleet was moving west.
During the afternoon of 18 June Japanese scout planes found TF 58. Ozawa decided not to risk an afternoon attack as this would have involved a night landing on Guam. Instead he prepared for an attack as soon as possible on the following morning.
At 20.00 on 18 June Admiral Spruance turned east in order to make sure he wasn't too far from Saipan. The Japanese had found the American fleet during the day, but the Americans had no firm information about the location of the Japanese.
Early on 19 June the Japanese fleet was heading north-east. It was then split into two parts. The Van (or Force C), commanded by Admiral Kurita, contained the light carriers Chitose, Chiyoda and Zuiho.
The main fleet consisted of Force A (Ozawa) and Force B (Joshima). It contained the fleet carriers Taiho, Zuihaku and Shokaku, the medium sized carriers Junyo and Hiyo and the light carrier Ryuho. At first the two groups sailed in the same direction and on the same line, but early in the day they turned south, with the van sailing a little to the east of the main fleet.
At 8.30am the Japanese launched their first strike, using aircraft from the van force. This attack contained 45 Zero fighter-bombers, 16 Zero fighters and 8 torpedo bombers.
Force A launched its first attack at 9.00. This was the largest attack, with 53 dive bombers, 27 torpedo bombers and 48 Zeroes. Finally Force B sent off a third wave of 47 aircraft at around 9.30. All three waves were in the air before the first Japanese aircraft reached the American fleet.
Further east the Americans were already involved in an air battle over Guam. As planned the Japanese had flown reinforcements in from Truk and other nearby bases, and a few aircraft had even arrived from Japan. The carrier's Hellcat fighters were engaged in a series of battles with these land based aircraft, but had defeated them by 10am.
In the meantime the Japanese fleet had suffered its first blow. As Force A was launching its aircraft it came past the submarine USS Albacore. The Albacore fired six torpedoes and at 9.05am scored a single hit. At first the damage didn’t look serious, but the damage control efforts were poor and the fleet carrier sank at 16.28.
At 10.00am the incoming Japanese carrier aircraft were detected on US radar. The Hellcats were sent up to intercept them. The Japanese aircraft had been detected when they were 150 miles from the fleet and most of them were intercepted around 50 miles away. These dog fights went disastrously badly for the Japanese. Earlier in the war their well trained pilots had been a match for the Americans, but that was no longer the case. Of the 69 aircraft from Force C, 42 were shot down and none reached the fleet. Force A's 128 aircraft suffered equally heavy losses, with over 100 aircraft shot down. About 20 reached the battle line, where most were shot down by anti-aircraft fire. A handful reached the carriers and did manage to inflict minor damage on the Wasp and Bunker Hill. Only thirty aircraft from these first two attacks managed to return to their carriers, where they reported great successes.
The attack from Force B was a flop. The aircraft had been sent too far to the north and so missed most of the American ships. Half of the force turned back, while the other half eventually spotted the northern end of the American line. A few bombs were dropped, but no damage was done. Some of these aircraft were lost when they attempted to land on Guam.
The Japanese suffered a third blow at 12.20pm. This time it was the submarine USS Cavalla that did the damage, hitting the Shokaku with three or four torpedoes. The Cavalla was the target of at least 105 depth charges, but survived. The same was not true for the Shokaku, which sank at 16.24.
At about 14.00pm Ozawa sent off a fourth attack. By now his available forces had been badly weakened, and he could only find 87 aircraft. These came from the Zuikaku, the only undamaged fleet carrier, and from the light carriers of Force C. This force was also misdirected, this time going too far south. The group had been ordered to land on Guam to rearm, so 49 aircraft made straight for the island only to find the Americans in control of the skies. Thirty of the forty nine aircraft were shot down before they could land. The other half of the force did attack the southernmost carrier task group, but most of these aircraft were shot down, again without inflicting any damage on the Americans.
The two damaged Japanese carriers sank within a few minutes of each other. Efforts to save Shokaku had been abandoned after three hours, but she exploded while her crew were still leaving the ship, and sank at 16.24. The Taiho fell a victim to her own damage control efforts. In an attempt to clear petrol fumes out of her, the ventilation system was turned on. This filled the ship with explosive fumes and caused a massive explosion. The orders were given to abandon ship, but at 16.28 she suffered a final fatal explosion and sank.
That night Admiral Ozawa considered sending his battleships to conduct a night attack on the American fleet. The Americans had also thought of the same idea and Admiral Willis A. Lee's battleships were posted west of the carriers to provide a screen. In the even Ozawa didn’t risk this attack.
The day had been a disaster for the Japanese. Ozawa had sent out 373 aircraft during the day, but only 130 of them had returned to the fleet. Many of these were too badly damaged to save, or suffered landing accidents, so by the end of the day he only had 102 operational aircraft left, having started with 430. The Americans only lost 23 aircraft in what became know as the 'Great Marianas Turkey Shoot'.
In contrast the Americans had lost 23 aircraft in battle and 6 to other causes. The battleship South Dakota had been hit by a bomb in the superstructure, the Indiana by a torpedo, but both ships only suffered minor damage.
Admiral Spruance had achieved one of the most important and one-sided naval victories of the Pacific War, but this wasn't entirely clear at the time. The loss of the two Japanese fleet carriers wasn’t known for some time, and his tactics had been entirely defensive. He was later criticised for failing to sink more Japanese carriers.
On 20 June Admiral Spruance attempted to make up for that. Just as Spruance didn't yet realise the extent of his victory, Ozawa didn't realise the extent of his defeat. Two carriers had been lost, but he believed that most of the missing aircraft were on Guam, while the surviving pilots claimed to have sunk several American carriers. Ozawa thus decided to rejoin his tankers, take on fuel and prepare to continue the battle.
The Americans spent most of 20 June attempting to find the Japanese fleet. At first they moved west, before at noon turning north. At 16.00 a scout from the Enterprise spotted the Japanese fleet. It was now late in the day and the attack would have to be carried out at extreme range, but Mitscher decided to risk it. With the landings now secure, Spruance gave him permission to attempt the attack, and at 16.24 an attacking force of 77 dive-bombers, 54 torpedo-bombers and 85 fighters set off towards the Japanese fleet, a total of 216 aircraft (twice as many as remained in the entire Japanese fleet).
Ozawa discovered that the Americans were coming at 16.15. The refuelling was abandoned before it began and he ordered the fleet to retreat north-west in an attempt to get out of range.
After a long chase the Americans caught up with the Japanese just before 7pm. The tankers were found first, and two were sunk by dive bombers. The rest of the force pressed on to attack the main Japanese fleet. Ozawa attempted to put up a fighter screen, but this was swept aside and another sixty-five Japanese aircraft were lost. The Americans only lost fourteen aircraft in the attack.
Three of the surviving seven Japanese carriers were hit during this attack. The Hiyo was hit by dive bombers and torpedo bombers and sank. The last of the fleet carriers, Zuikaku, was hit by several bombs which started fires. She was very badly damaged and only just survived. It took until August to complete repairs. The carrier Chiyoda suffered heavy damage to her flight deck. The battleship Haruna and cruiser Maya were also damaged.
Of the 216 aircraft originally sent out, 202 were now attempting to find their way back to the fleet in the dark and with fuel running short. Admiral Mitscher decided to take the risk of turning on every possible light on his ships in an attempt to guide the aircraft back to safety. A total of 122 managed to land on a carrier (if not always the right carrier), but 80 aircraft either ditched when they ran out of fuel or crashed attempting to land at night. A massive air-sea rescue effort followed, and all but 16 pilots and 33 aircrew were saved.
Aftermath and Conclusion
The battle of the Philippine Sea was the last carrier battle of the Pacific War. The Japanese navy lost three carriers (Hiyo, Shokaku and Taiho) with three more damaged (Ryuho suffered minor damage from near misses, Zuikaku was badly damaged by bombs, Chiyoda suffered bad damage to the deck) . The Japanese lost nearly 500 aircraft and 450 pilots (including carrier and land based aircraft). Japanese naval aviation never recovered from this blow. Even the Japanese recognised this, and at the last great naval battle of the war, the battle of Leyte Gulf, the surviving carriers could only be used as a decoy force.
It took some time for the US Navy to realise how significant a victory they had won in the Philippine Sea. The survival of six of the Japanese carriers and all of their battleships gave the false impression that a chance of a great victory had been lost. Even some of the experienced American carrier admirals believed that a major victory had eluded them (including Mitscher himself). The truth still hadn’t dawned at Leyte Gulf, where the main American fleet did indeed dash north in an attempt to intercept the Japanese carriers, only to find them almost empty of aircraft and no threat at all.