Mitscher’s attacking instincts were by now thoroughly roused and when Cavalla radioed in at 0730 hours to say that the Japanese warships she had seen at midnight were by now 700nm (1296km) from Saipan and closing, he returned to plead his case for aggressive action. Mitscher proposed yet again a high speed chase to the southwest to get within a carrier strike of the enemy before nightfall and wished to commit Lee’s battle group to a surface action as the night proceeded. Spruance was unconvinced by this strategy and preferred to play a waiting game. He sensed that the various elements of the Japanese fleet would be bound eventually to seek him out and he wanted to be in a strong position to deal with them when they did. As a result, Mitscher’s request was turned down once more in favour of preserving a consolidated shield for Turner’s amphibious fleet at Saipan and running aerial sweeps to the westward to try to locate the various elements of the Japanese fleet that had come out to contest the invasion of the Marianas. A kind of cat and mouse duel proceeded as both sides stalked the other on 18 June. In the middle of the afternoon Ozawa finally received the first reconnaissance reports specifying the location of Mitscher’s carriers. He decided to keep out of range for the time being and surprise them with a massive raid the next day. Although American reconnaissance aircraft were unable to establish the whereabouts of the Japanese fleet, Nimitz sent a signal at 2230 hours reporting that a shore-based DF station had managed to get a fix on the enemy flagship from a signal communication that Ozawa had made to Guam. It put him roughly 350nm (648km) from TF 58 and conformed with Cavalla’s report of the estimated course and speed of the Japanese force. Mitscher once again sought to change course, close the Japanese during the rest of the night and seek action at first light on the following day. Spruance once again demurred not knowing whether the Japanese fleet was concentrated or divided, and uneasy about quitting what he saw as his primary responsibility to protect Turner’s fleet. So to the maximum frustration of the naval aviators, Spruance decided to wait for corroboration of the DF report. He might have granted Mitscher’s wish had he received the report issued at 0115 hours from a USN patrol bomber flying boat indicating a radar fix on Kurita’s fleet close to the DF location. This radio signal wasn’t picked up and so the waiting continued. At first light on 19 June Mitscher sent off his combat air patrols to locate the enemy carriers and Ozawa opted for a similar response sending forty-three planes airborne at 0600 hours to discover the latest whereabouts of TF 58.
At 0730 hours Ozawa began receiving the information he sought and preparations for the launching of his carrier planes against the three US carrier groups located about 300-380nm (556-704km) away were immediately put in hand. Instead of sending his planes against them in one or two huge waves, however, Ozawa was soon to discover that one of his subordinate commanders, Rear-Admiral Sueo Obayashi, had pre-empted him by unilaterally sending off two `Kate’ pathfinders at 0800 hours followed by a mixed force of seventy planes drawn from his three light carriers Chitose, Chiyoda and Zuiho some twenty-five minutes later. Ozawa’s three carriers in Group A (Shokaku, Taiho and Zuikaku) eventually flew off 131 planes at 0856 hours, and Joshima’s three carriers in Group B (Hiyo-, Junyo and Ryuho) got theirs airborne a little later. In all 374 aircraft were finally committed to the attack on the American carriers. Picked up on radar while still at great distance from TF 58, each of the four waves of attacking planes was successively confronted by a superior force of Hellcats which cut most of them to pieces. Of those that got beyond the US fighter screen to attack the warships beyond it, one registered a bomb hit on the battleship South Dakota, a torpedo-bomber actually crashed into the side of the battleship Indiana wiping out the plane but not the capital ship, while two others managed near-misses on the carriers Bunker Hill and Wasp as well as the heavy cruiser Minneapolis. This was the extent of their success, however, since most of the planes that had eluded the Hellcats were then subject to withering A. A. fire from the ships. While the Americans lost a total of thirty-one fighter planes in these sorties on 19 June, the Japanese lost 244 carrier planes in the four raids on TF 58, and somewhere between thirty and forty-nine more planes on Guam. Twenty-two other carrier planes would be lost when the US submarines Albacore and Cavalla entered the act by torpedoing and crippling the carriers Shokaku and Ozawa’s flagship Taiho respectively. Both carriers exploded and sank during the afternoon carrying 2,913 of their officers and crew down with them. Ozawa and his close staff were not among them. They had been transferred in stages to the heavy cruiser Haguro once it had become clear that the carrier could no longer function as the nerve centre of the fleet and was, in fact, living on borrowed time. So ended a day in which the art of the counter-attack had decisively prevailed. It would henceforth be known rather irreverently in the annals of the Pacific war as `The Great Marianas Turkey Shoot’.
Unaware for many hours of the scale of his own losses, Ozawa still remained convinced that his carrier force had inflicted severe damage upon the Americans – a distorted opinion shared by his C-in-C Admiral Toyoda – and both were more than willing to take on the enemy again once their own carriers had been refuelled and the 1st Mobile Fleet had shed its damaged warships and redeployed others for further training. Wishful thinking and staggering overconfidence gripped both men as plans were developed for what they erroneously assumed would be a mopping-up exercise against their battered opponents on 22 June. Mitscher and Spruance had other ideas and were more in tune with objective reality. There was no reason for them to wait for two days to accomplish the next stage of their operation against the Japanese and scouting missions were dispatched early on 20 June to try to discover the location of the wounded foe. It was mid-afternoon before two groups of Ozawa’s fleet were spotted more than 200nm (370km) from TF 58. Mitscher was all for tackling the enemy even though at such distance his planes could not afford to dwell over the target but would have to release their pay loads and then head for home immediately in order to have just enough fuel to get back to their carriers. At 1605 hours the enemy’s estimated position was revised putting them even further away and at the extreme range of Mitscher’s planes. Supported by Spruance, he decided that the risks were worthwhile. His own carriers turned into the wind at 1621 hours and began flying off 226 aircraft shortly thereafter. Once they had cleared the decks, Mitscher turned his ships back to the west and made speed to cut the gap between them and the 1st Mobile Fleet to try to give his pilots a platform to land on when they returned from the attack on Ozawa’s warships.
By this time Ozawa had transferred his flag to the Zuikaku, and it was on this carrier at 1715 hours that he learnt from one of his own reconnaissance planes that the Americans were in more formidable shape than he had previously supposed. Reckoning that his ships were now vulnerable to a renewed carrier thrust, Ozawa ordered his fleet onto the defensive at 1754 hours and nine minutes later they began picking up a radar trace of a wave of approaching planes. Before the American planes got to the Zuikaku, some had fastened upon the oil tankers hitting two so badly that they eventually had to be scuttled and damaging the seaplane carrier Hayasui into the bargain. Then it was turn of the denuded Carrier Group A to feel the wrath of the American pilots. Although struck many times by bombs and in a fiery and unstable condition, the Zuikaku was saved by her crew’s timely damage control efforts. A well-directed torpedo could have meant the end for the struggling carrier, but the flight wing had already used theirs with damaging effect against the battleship Haruna and the heavy cruiser Maya and there were no surplus ones available to finish her off. Another flight wing took on Carrier Group B attacking all three carriers. Junyo, the flagship of Rear- Admiral Joshima, was bombed twice and received no less than six near-misses, whereas Ryuho, protected to some extent by Nagato’s 16-inch (406mm) guns, only received one near-miss. Hiyo-, however, was not so fortunate receiving two massive torpedo hits that wrecked her hull, stopped her dead in the water and ultimately led to her fiery end a couple of hours later. Other attacks on the warships of Kurita’s former Vanguard concentrated on the light carrier Chiyoda and the battleship Haruna, both of which were hit several times and received several near-misses, but even so they and the heavy cruiser Maya somehow avoided the fate of the Hiyo- – the only ship to sink as a result of this series of attacks. Once again, however, the main Japanese casualties were their carrier aircraft. Another sixty-five were destroyed in the afternoon’s attacks, leaving a mere thirty-five for use by Ozawa’s entire fleet thereafter. It was manifestly obvious that the 1st Mobile Fleet was in a dire state; three of its nine carriers and over 300 planes and their aircrews had been forfeited without denting the US 5th Fleet at all. There were no crumbs of comfort for the stunned Ozawa and Toyoda as they had to come to terms with the fact that the carrier fleet, as they had known it, had been consigned to history. What was left of it was incapable any longer of prosecuting a forward policy in the Pacific. While the Battle of the Philippine Sea marked the end of an era, it had a sting in the tail for the Americans as well. Apart from the nineteen carrier planes that were lost in combat in these final raids, another eighty perished as they tried to make their way back to TF 58 as the evening of 20 June drew on, either running out of fuel and being forced to land in the sea or crashing on the illuminated decks of the carriers and in some cases attempting to do so on other warships as well. Amazingly, only sixteen pilots and thirty-three air crew lost their lives in these hair-raising exploits. Although both Mitscher and Ozawa were still inclined to press ahead with some of their forces during the night in an effort to continue grappling with the enemy, neither had the final say in the matter. Before midnight on 20 June Toyoda finally ordered what was left of the 1st Mobile Fleet to withdraw from the scene and steam northwestwards to Okinawa putting as many miles as possible between it and TF 58 during the hours of darkness. Spruance’s caution returned to stifle Mitscher’s plans to take any further initiative. In his eyes, a famous victory had already been won, so why should he jeopardise it by adopting a risky nighttime strategy? By the time dawn appeared and he was finally prepared to leave Kelly Turner’s vulnerable transports exposed to external threats in order to pursue Ozawa’s forces, the Japanese were forging ahead through the Pacific towards the Ryukyu Islands and out of harm’s way. Spruance had missed a golden opportunity to strike an even bigger blow against the IJN than had already been achieved in the Philippine Sea over the course of the last few days. It was a decision he would come to rue for the rest of his life. He had chosen the conservative option. While it was perfectly defensible on the grounds that he had preserved the fleet for the long, arduous slog ahead of it in the Marianas, the overwhelming suspicion is that on this occasion a bolder strategy would have been a better option in a calculated bid to put the wounded enemy to the sword. Once again, it was a question of what might have been rather than what was.