During the Battle of the Coral Sea, United States Navy aircraft carrier aircraft attack and sink the Imperial Japanese Navy light aircraft carrier Shōhō; the battle marks the first time in the naval history that two enemy fleets fight without visual contact between warring ships.
The Battle of the Coral Sea, from 4 to 8 May 1942, was a major naval battle between the Imperial Japanese Navy (IJN) and naval and air forces of the United States and Australia. Taking place in the Pacific Theatre of World War II, the battle is historically significant as the first action in which aircraft carriers engaged each other and the first in which the opposing ships neither sighted nor fired directly upon one another.
In an attempt to strengthen their defensive position in the South Pacific, the Japanese decided to invade and occupy Port Moresby (in New Guinea) and Tulagi (in the southeastern Solomon Islands). The plan, Operation Mo, involved several major units of Japan's Combined Fleet. They included two fleet carriers and a light carrier to provide air cover for the invasion forces, under the overall command of Admiral Shigeyoshi Inoue.
The U.S. learned of the Japanese plan through signals intelligence and sent two U.S. Navy carrier task forces and a joint Australian-American cruiser force to oppose the offensive, under the overall command of U.S. Admiral Frank J. Fletcher.
On 3–4 May, Japanese forces successfully invaded and occupied Tulagi, although several of their supporting warships were sunk or damaged in surprise attacks by aircraft from the U.S. fleet carrier Yorktown. Now aware of the presence of enemy carriers in the area, the Japanese fleet carriers advanced towards the Coral Sea with the intention of locating and destroying the Allied naval forces. On the evening of 6 May, the two carrier forces came within 70 nmi (81 mi; 130 km) of each other, unbeknownst to anyone. On 7 May, both sides launched airstrikes. Each mistakenly believed they were attacking their opponent's fleet carriers, but were actually attacking other units, with the U.S. sinking the Japanese light carrier Shōhō and the Japanese sinking a U.S. destroyer and heavily damaging a fleet oiler, which was later scuttled. The next day, each side found and attacked the other's fleet carriers, with the Japanese fleet carrier Shōkaku damaged, the U.S. fleet carrier Lexington critically damaged and later scuttled, and the fleet carrier Yorktown damaged. With both sides having suffered heavy losses in aircraft and carriers damaged or sunk, the two forces disengaged and retired from the area. Because of the loss of carrier air cover, Inoue recalled the Port Moresby invasion fleet with the intention of trying again later.
Although a victory for the Japanese in terms of ships sunk, the battle would prove to be a strategic victory for the Allies in several ways. The battle marked the first time since the start of the war that a major Japanese advance had been checked by the Allies. More importantly, the Japanese fleet carriers Shōkaku and Zuikaku, the former damaged and the latter with a depleted aircraft complement, were unable to participate in the Battle of Midway the following month, but Yorktown participated on the Allied side, which made for rough parity in aircraft between the adversaries and contributed significantly to the U.S. victory. The severe losses in carriers at Midway prevented the Japanese from reattempting to invade Port Moresby by sea and helped prompt their ill-fated land offensive over the Kokoda Track. Two months later, the Allies took advantage of Japan's resulting strategic vulnerability in the South Pacific and launched the Guadalcanal Campaign. That and the New Guinea Campaign eventually broke Japanese defenses in the South Pacific and were significant contributors to Japan's ultimate surrender, marking the end of World War II.