Coral Sea, battle of

Coral Sea, battle of, first-ever major naval action between carriers and the first in which the opposing ships never sighted one another. It was fought from 4 to 8 May 1942 during the Pacific war between units of the Japanese and US navies which were attempting, respectively, to establish and to prevent a Japanese landing at Port Moresby, Papua. It was, like many battles, much influenced by the weather (see meteorological intelligence).

In overall control of the Japanese forces was Vice-Admiral Inoue Shigeyoshi whose three invasion convoys were assembled at Truk and Rabaul. The largest convoy was destined for Port Moresby while the others were to establish seaplane bases on Tulagi Island and in the Louisiades. Protecting the convoys was a covering force, commanded by Rear-Admiral Gotō Aritomo, which comprised the light carrier Shōhō, four heavy cruisers, and one destroyer; and a striking force, commanded by Vice-Admiral Takagi Takeo, which consisted of the fleet carriers Shōkaku and Zuikaku, two heavy cruisers, and six destroyers.

The Japanese anticipated the Americans would intervene, and they planned to catch any attacking force in a pincer movement while the main invasion force slipped into Port Moresby. If what the Japanese called Operation MO succeeded, Australia would be isolated and within the range of Japanese aircraft. However, the US Pacific Fleet's C-in-C, Admiral Nimitz, had been alerted early to the Japanese invasion by ULTRA intelligence and had assembled two carrier task forces around the fleet carriers Lexington and Yorktown, and a task force of Australian and US cruisers under a British naval officer, Rear-Admiral John Crace.

The Tulagi invasion force landed unopposed on 3 May, but the next day its ships were attacked by aircraft from Yorktown and a destroyer was beached and several smaller vessels sunk. Two days later the three Allied task forces assembled 400 miles south of Guadalcanal under the command of Rear-Admiral Fletcher aboard Yorktown, and sailed north-west to intercept the Port Moresby invasion transports and Tagaki's carriers. At dawn on 7 May Fletcher ordered Crace to forge ahead to intercept the transports, and then turned north to where he supposed Tagaki to be. However, inaccurate air reconnaissance guided Yorktown's attack group not on to the carriers but on to the invasion convoy's escort, and the threat of their presence was enough to make the convoy withdraw to await the outcome of the main battle. The attack group from Lexington then found Shōhō and, aided by Yorktown's aircraft, sank her with the loss of only three planes. Meanwhile Crace, when he heard the convoy had turned back, withdrew.

Fletcher, now without air cover and highly vulnerable to attack, only learned after midday that, quite contrary to his expectations, the Japanese carriers were somewhere astern of him and had sunk two of his ships. For Tagaki, like Fletcher earlier, had been misled into launching air strikes against a subsidiary target—a tanker and its escorting destroyer which Fletcher had ordered to drop astern the previous night.

Next morning, 8 May, the two sides located each other and launched all-out strikes. In the air they were almost equal in numbers, 121 Japanese to 122 American aircraft, but the Japanese types were superior to their American equivalents. The first American attack, from Yorktown, damaged Shōkaku. Aircraft from Lexington also hit her and she turned north trailing smoke, but Zuikaku was not even located. Meanwhile, Japanese aircraft were attacking the American carriers with devastating success. Their strike group contained a better balance of different types of aircraft than the Americans', and these were more accurately directed on to their targets. Too few American aircraft could be launched to defend the carriers; Lexington was hit by bombs and torpedoes, and had to be sunk after a generator spark set off a huge explosion. Yorktown, too, was damaged, but the Japanese failed to seal their victory by pressing home their attack. The battle, therefore, though a tactical success for Tagaki, was a strategic failure for Inouye who was later criticized for not persisting with the invasion of Port Moresby after Crace had withdrawn.

The loss of Lexington was a severe blow to the Americans, but neither Shōkaku, because of damage, nor Zuikaku, because her aircraft strength was so depleted, was able to take part in the critical battle of Midway the following month, an absence that helped tip the scales there in favour of the Americans.