Battle of the Coral Sea (1942): The First Carrier Battle

The Battle of the Coral Sea, fought from 4 to 8 May 1942, was the first naval battle in history in which the opposing fleets never saw each other: every attack was made by aircraft flying from carriers. American and Australian forces clashed with a Japanese fleet covering an invasion of Port Moresby in Papua. Japan sank more ships, but it called off the invasion, the first time its expansion in the Pacific had been checked.

Background

By the spring of 1942 Japan had conquered the Philippines, Malaya, Singapore and the Dutch East Indies, and had established a major base at Rabaul on New Britain. Its navy now planned to extend the defensive perimeter further south. Operation MO aimed to take Tulagi in the Solomon Islands for a seaplane base and to land troops at Port Moresby, the main Allied base on the south coast of New Guinea. From there, Japanese aircraft could reach northern Australia and the sea routes between Australia and the United States.

The operation was directed by Vice Admiral Shigeyoshi Inoue, commander of the Fourth Fleet at Rabaul. It involved an invasion convoy, a covering group with the light carrier Shōhō, and a carrier striking force under Vice Admiral Takeo Takagi built around the large fleet carriers Shōkaku and Zuikaku, under Rear Admiral Chūichi Hara.

American codebreakers in Hawaii and Allied analysts in Melbourne had partly broken the Japanese navy’s operational code, JN-25. By mid-April they had enough information for Admiral Chester Nimitz, commander of the Pacific Fleet, to predict an attack on Port Moresby. He sent Task Force 17 under Rear Admiral Frank Jack Fletcher, with the carrier USS Yorktown, and Task Force 11 under Rear Admiral Aubrey Fitch, with USS Lexington. An Allied cruiser force including Australian warships, commanded by the Australian-born Royal Navy officer Rear Admiral John Crace, joined them.

The opening moves

Japanese troops landed unopposed at Tulagi on 3 May 1942. The next day, 4 May, aircraft from Yorktown attacked shipping there, sinking the destroyer Kikuzuki and several smaller vessels, though with less effect than the American aircrews believed. Both carrier forces then manoeuvred in the Coral Sea, searching for each other in poor weather, with long-range reconnaissance aircraft and inaccurate sighting reports adding to the confusion.

On 7 May each side struck at what it believed was the enemy’s main force and found something else. Japanese aircraft located the oiler Neosho and the destroyer Sims, which a search plane had mistaken for a carrier and a cruiser. Sims was sunk and Neosho was left a wreck, to be scuttled on 11 May. American aircraft, meanwhile, found the Shōhō and sank it within minutes. Lieutenant Commander Robert Dixon’s radio report, “Scratch one flattop!”, became one of the best-known phrases of the Pacific War.

Fletcher had detached Crace’s cruisers to block the southern exit of the Jomard Passage, the route the invasion convoy would take. On 7 May they were attacked by Japanese land-based bombers and, by mistake, by American B-17s from Australia, but escaped serious damage. With the Shōhō lost and enemy carriers still at large, Inoue ordered the invasion convoy to turn back temporarily.

The carrier duel of 8 May

On the morning of 8 May the two carrier forces found each other almost simultaneously and launched full strikes. American dive bombers hit the Shōkaku three times, wrecking its flight deck and forcing it out of the battle, while Zuikaku escaped under cover of a rain squall. At about the same time Japanese torpedo bombers and dive bombers attacked the American carriers. Yorktown was hit by one bomb and damaged by near misses. Lexington was struck by two torpedoes and two bombs.

At first Lexington’s crew seemed to have the damage under control, and the carrier continued to recover aircraft. In the early afternoon, however, fuel vapour from ruptured tanks ignited, causing a series of explosions and fires that could not be contained. The crew abandoned ship in an orderly way, and most were rescued. That evening the destroyer USS Phelps sank the burning carrier with torpedoes.

Both sides withdrew. Takagi had lost too many aircraft to continue, and Inoue postponed the Port Moresby landing. It was never attempted by sea again. Japan instead tried to reach the town overland across the Owen Stanley Range, leading to the Kokoda Track campaign, and with a landing at Milne Bay.

By the numbers

Figures for aircraft and deaths vary between sources; those above are commonly cited estimates.

Key people

• Frank Jack Fletcher (1885–1973): commanded the Allied carrier forces and made the main tactical decisions.
• Aubrey Fitch (1883–1978): commanded the Lexington group and the carrier air operations on 8 May.
• John Crace (1887–1968): led the Allied cruiser support group, whose position helped protect the approach to Port Moresby.
• Shigeyoshi Inoue (1889–1975): Japanese commander of Operation MO, who decided to postpone the invasion.
• Takeo Takagi (1892–1944) and Chūichi Hara (1889–1964): led the Japanese carrier striking force.

Consequences

In terms of ships sunk, Japan came out ahead: a large American fleet carrier was worth far more than the small Shōhō. But Japan had failed to achieve its objective. Its strategic consequence was felt a month later at the Battle of Midway. The Shōkaku needed months of repair, and the Zuikaku, though undamaged, had lost so many trained aircrew that it could not be made ready in time. Japan therefore went to Midway with four fleet carriers instead of six.

The damaged Yorktown returned to Pearl Harbor, where it was repaired in about three days and sailed for Midway, where its aircraft played an important part before it was sunk. Both navies learned lessons at the Coral Sea about fighter protection, damage control and the difficulty of finding an enemy fleet at sea. The Americans, in particular, improved their procedures for handling aviation fuel after the loss of Lexington, which had been caused more by vapour explosions than by the bombs and torpedoes themselves.

For Australia the battle had special significance. It was fought close to its shores at a time when Japanese aircraft had already bombed Darwin and when many Australians feared invasion. Although Japan had by then decided against invading Australia, the battle protected Port Moresby and the sea links with the United States, and it is remembered in Australia as the moment when the threat from the sea receded.

Timeline

• 1942, March: Japan decides to take Port Moresby and Tulagi in Operation MO.
• 1942, April: Allied codebreakers detect the plan; Nimitz sends two carriers south.
• 1942, 3 May: Japanese forces occupy Tulagi.
• 1942, 4 May: Yorktown’s aircraft attack shipping at Tulagi.
• 1942, 7 May: Shōhō is sunk; Japanese aircraft sink USS Sims and cripple Neosho; the invasion convoy turns back.
• 1942, 8 May: The carriers exchange strikes; Shōkaku and Yorktown are damaged and Lexington is lost.
• 1942, 11 May: The wreck of Neosho is scuttled after its survivors are rescued.
• 1942, 4–7 June: Without Shōkaku and Zuikaku, Japan is defeated at Midway.

Why it matters

The Coral Sea was the first battle between aircraft carriers and showed that naval warfare had changed for good. It halted Japan’s advance by sea for the first time, protected Port Moresby and the links to Australia, and weakened the Japanese fleet just before Midway. In Australia it is still commemorated each year as a turning point in the defence of the country.