Battle of the Philippine Sea

The battle of the Philippine Sea in June 1944, was a major defeat inflicted by the U.S. Navy on the Japanese Navy in World War II, Pacific. It marked the end of offensive Japanese capabilities, and gave the U.S. control of Guam, Saipan and Tinian islands that provided air bases within range of B-29 bombers targeted at Japan's home islands. It was entirely an air battle, in which Americans had all the technological advantages. It was the largest naval battle in history, to day, surpassed only by the Battle of Leyte Gulf in October 1944.

Plans

In strategic terms the US Navy began a long movement across the Pacific, seizing one island base after another. Not every Japanese stronghold had to be captured; some, like the big bases at Truk, Rabaul and Formosa were neutralized by air attack and then simply leapfrogged. The goal was to get close to Japan itself, then launch massive strategic air attacks and finally an invasion. The US Navy did not seek out the Japanese fleet for a decisive battle, as Mahanian doctrine would suggest; the enemy had to attack to stop the inexorable advance. The climax of the carrier war came at the Battle of the Philippine Sea. Airfields on the island of Saipan--within B-29 range of Tokyo--was the objective as 535 ships began landing 128,000 Army and Marine invaders on June 15, 1944. The achievement in planning such a complex logistical operation in just ninety days, and staging it 3,500 miles from Pearl Harbor was indicative of American logistic superiority. (The previous week an even bigger landing force hit the beaches of Normandy--by 1944 the Allies had resources to spare.)

Japan’s strategy

Japan had to save Saipan--the only possible defense was to sink the 5th Fleet covering the landing, a fleet with 15 big carriers and 956 planes, plus 28 battleships and cruisers, and 69 destroyers. Tokyo sent Vice Admiral Jisaburo Ozawa with nine-tenths of Japan's fighting fleet--it was about half the size of the American force, and included nine carriers with 473 planes, 18 battleships and cruisers, and 28 destroyers. Ozawa's pilots boasted of their fiery determination, but they had only a fourth as much training and experience as the Americans. They were outnumbered 2-1 and used inferior equipment. Ozawa had anti-aircraft guns but lacked proximity fuzes and good [[]rada]r.

With the odds stacked against him, Ozawa had to gamble on surprise and a trick strategy. His planes carried more gasoline because they were not weighted down with protective armor; they could attack at 300 miles, and could search a radius of 560 miles. (The high speed and maneuvering at the attack scene consumed gasoline rapidly, and accounts for the difference.) The heavier Hellcats could only attack to 200 miles, and only search to 325. Ozawa's plan therefore was to use his advantage in range by positioning his fleet 300 miles out, forcing the Americans to search over 150,000 square miles of ocean just to find him. The Japanese ships would stay beyond American range, but their planes would have enough range to strike the American fleet. They would hit the carriers, land at Guam to refuel, then hit the Yankees en route back to their carriers. Ozawa counted heavily on the 500 or so ground- based planes that had been flown ahead to Guam and other islands in the area. He hoped that a few "lucky" hits like those at Midway would do the job.

Spruance was in overall command of the 5th Fleet. A brilliant long-range strategist, in battle he was highly cautious and inflexible once he had made up his mind. A battleship sailor, he still did not fully appreciate the power of his carriers. The Japanese plan would have failed if the much larger American fleet had closed on Ozawa and attacked aggressively; Ozawa had the correct insight that the unaggressive Spruance would not attack. Admiral Mitscher, in tactical command of the Task Force 58, with its 15 carriers, was aggressive but Spruance vetoed Mitscher's plan to hunt down Ozawa because Spruance's personal doctrine made it his first priority to protect the soldiers landing on Saipan. Spruance still did not understand the new carrier doctrine, and he did not realize that Ozawa was a Mahanian looking for a decisive battle that would destroy the American carriers.

The battle

The forces converged to the largest sea battle ever fought to date. Ozawa's strategy worked to perfection--on paper; in real water and fresh air it disintegrated. Over the previous month American destroyers had depth charged 17 of the 25 submarines Ozawa had sent ahead. Repeated raids destroyed the Japanese land planes based on Guam and wrecked the airfields. When Ozawa finally launched, his strategy already was in ruins. His cleverness outdid itself, for at such long range the attackers straggled in, allowing the Yankees to take patient aim and knock them down one at a time. If they had arrived simultaneously it might have been a real battle. Following Nimitz's directive, the carriers all had combat information centers that performed brilliantly. They interpreted the flow of radar data instantaneously and radioed orders to the Hellcats to intercept the bandits 50 or 60 miles out. It was a stunning performance--one pilot dubbed it the "Great Marianas Turkey Shoot." The few surviving attackers encountered massive antiaircraft fire with proximity fuzes. Over a period of eight hours one American warship was slightly damaged while one Japanese plane burst into flames every two minutes.

On the second day scout planes finally located Ozawa's fleet at 275 miles; submarines sank two of its carriers. Mitscher launched 230 torpedo planes and dive bombers to attack immediately. He then discovered that the enemy was actually another 60 miles further off--out of round-trip range. Unless he recalled his planes it was unlikely that his pilots would make it back. Mitscher was a fighter who believed in the new carrier doctrine; he did not recall the planes. They sank one carrier, and badly damaged three of the remaining six. Twenty American planes were shot down, but 80 crashed on the way back for lack of fuel.

Naval aircraft at the time had virtually no night navigation capability, especially in the single-seat fighters. Without guidance, they were apt to run out of fuel, and, even if they could make a successful water crash landing in darkness, were unlikely to survive.

Standard doctrine was to keep the warships absolutely blacked out, as submarines could see surprisingly small lights. Mitscher, however, took on a calculated risk. He had been growing increasingly weak physically, so his four-word order was a near-croak — that electrified his command center.<ref name=Kitchen>Kitchen, Ruben P., Jr. (1998), TURN THE LIGHTS ON...OUR PILOTS WILL LIVE!

"Turn on the lights", he ordered. Every ship lit every light, with searchlights pointed straight up. They were a perfect submarine target — but the lost pilots could see their way back. Pilots were not fussy about landing on their own carrier; indeed, many, with neither the carriers nor pilots trained for night operations, made crash landings on any carrier they could find. In such cases, as soon as the aircrew jumped out, the deck sailors often pushed the aircraft overboard, clearing the deck for the next.

Thanks to heroic effort and precise sea rescue technique, all but 50 of the aircrew survived. The Japanese, by contrast, generally ignored their downed pilots. Spruance has been sharply criticized and as sharply defended for a doctrine that allowed Ozawa's six remaining carriers to escape. Critics say that if he had been more aggressive they might have been sunk. Defenders say that the Japanese would find it harder to replace the lost pilots, without which the carriers were useful for little except decoy operations — their role at the Battle of Leyte Gulf.

But superior resources and training won out. The US lost 130 planes and 76 men in one of the greatest victories in world naval history. Japan lost 450 planes, three carriers and 445 of its best remaining pilots. Saipan was lost and soon bulldozers were clearing super-long airfields for the Superfortress, the B-29 bombers now in range of Tokyo.