Battle of the Coral Sea, (May 4–8, 1942) World War II naval and air engagement in which a U.S. fleet turned back a Japanese invasion force that had been heading for strategic Port Moresby in New Guinea. By the end of April 1942 the Japanese were ready to seize control of the Coral Sea (between Australia and New Caledonia) by establishing air bases at Port Moresby in southeastern New Guinea and at Tulagi in the southern Solomons. But Allied intelligence learned of the Japanese plan to seize Port Moresby and alerted all available sea and air power. When the Japanese...