The Battle of the Coral Sea was the first major engagement between the Americans and the Japanese after the Attack on Pearl Harbor, and also the first battle between two fleets of aircraft carriers in history.
Japan was in a period of military expansion in Southeast Asia, approaching the Coral Sea, located northeast of Australia. Under the codename Operation MO, their targets were Port Moresby in New Guinea, and Tulagi in the Solomon Islands. If these were captured, the communication lines between Australia and the United States would have been jeopardized.
However, the Americans had discovered the Japanese intentions through signals intelligence. Based on them, the U.S. Navy sent the task forces of two aircraft carriers to the Coral Sea.
By Shun Zero (Own work) [CC BY-SA 3.0 (http://creativecommons.org/licenses/by-sa/3.0/)], via Wikimedia Commons
The Battle of the Coral Sea begun on May 4, 1942, when the Japanese occupied the undefended island of Tulagi and planes from the U.S. carrier Yorktown sank four Japanese ships of the invasion fleet. Neither the Japanese nor the Americans did not know the location of the enemy carriers. On May 7, both sides found something, but it was not what they thought to be.
The Japanese reconnaissance planes confounded a U.S. tanker and a destroyer with an aircraft carrier accompanied by its escort. Therefore, aircraft from the two fleet carriers, Shōkaku and Zuikaku, which were the most important warships of the Japanese task force sent to the Coral Sea, attacked the two U.S. ships, sinking them.
For their part, the Americans found the ships of the invasion force heading for Port Moresby, escorted by the light aircraft carrier Shōhō, and supposed it was the main Japanese task force. The U.S. Navy sent all available aircraft from the carriers Lexington and Yorktown, resulting in the sinking of Shōhō.
However, on the morning of 8 May, reconnaissance planes from the both sides discovered almost simultaneously the real position of the enemy carriers. The U.S. and Japanese aircraft took off from carriers, heading towards the opposing fleet.
SBD Dauntless dive bombers managed to hit Shōkaku with three 1,000 lb (450 kg) bombs, while all TBD Devastator torpedo bombers missed the targets. Seriously damaged and with high casualties, Shōkaku was withdrawn from the battle by the Japanese. The other carrier, Zuikaku, better hidden by clouds, escaped untouched.
On the other side, Lexington was hit by two torpedoes from Nakajima B5N bombers, while an Aichi D3A dive bomber hit Yorktown with a bomb of 250 kg (550lb). Lexington would be scuttled a few hours after attack following the explosions that triggered uncontrollable fires.
The losses of aircraft and severe
damages sustained by the carriers prompted the both sides to disengage
from combat. Unable to provide an adequate air cover, the Japanese
decided to postpone the invasion of Port Moresby.
Although the battle ended indecisively, its outcome raised the American morale because the Japanese had been stopped from their triumphant march.