Battle of the Coral Sea

The Battle of the Coral Sea, fought from 4 to 8 May 1942 off the north-east coast of Australia, was the first battle in which aircraft carriers fought each other, and the first naval battle in which the opposing ships never saw or fired directly at one another. Japan lost fewer ships, but American and Australian forces stopped its attempt to capture Port Moresby by sea, the first time in the Pacific War that a Japanese invasion force had been turned back.

After Pearl Harbor, the Empire of Japan conquered a vast area reaching as far as New Britain, home of its base at Rabaul. To protect that base and bring northern Australia within range of its aircraft, the navy planned Operation MO: the seizure of Tulagi in the Solomon Islands and of Port Moresby on the south coast of New Guinea. Admiral Shigeyoshi Inoue commanded the operation, which was supported by the fleet carriers Shōkaku and Zuikaku and the light carrier Shōhō.

American codebreakers had made rapid progress against the Japanese navy's main code, and by late April they could read a large share of its messages. Learning that Port Moresby was the probable target, Admiral Chester Nimitz sent the carriers Yorktown and Lexington, under Rear Admiral Frank Jack Fletcher, together with a joint Australian and American cruiser force under the Australian Rear Admiral John Crace.

Japanese troops occupied undefended Tulagi on 3 May, and the next day Yorktown's aircraft struck the landing force, sinking a destroyer and several smaller vessels. For the next two days the opposing carrier fleets searched for each other, at one point coming within about 70 nautical miles in darkness without knowing it. On 7 May both sides attacked the wrong targets. Japanese aircraft found and sank the destroyer Sims and crippled the oiler Neosho, which their scouts had mistaken for a carrier. American aircraft, following a garbled sighting report, came upon the invasion covering force instead and sank Shōhō. A Japanese dusk strike against the American carriers lost many aircraft.

On the morning of 8 May the two main forces at last located each other and launched simultaneous strikes. American dive bombers hit Shōkaku with three bombs, wrecking her flight deck and forcing her to withdraw, while Zuikaku escaped under a rain squall. Japanese torpedo and dive bombers struck both American carriers. Yorktown was damaged by a bomb, and Lexington was hit by two torpedoes and bombs. Her fires were brought under control, but leaking petrol vapour later caused a series of explosions, and in the evening she was abandoned and sunk by an American destroyer. Both sides then withdrew. With his air cover weakened, Inoue recalled the Port Moresby invasion convoy and postponed the operation.

According to standard figures, the Americans lost a fleet carrier, a destroyer, an oiler and 69 aircraft, with about 715 men killed; the Japanese lost a light carrier, a destroyer and several smaller ships, between 69 and 97 aircraft and 966 men. Measured by ships sunk, Japan had the better of the battle, but strategically it was an Allied success, since the seaborne invasion of Port Moresby was abandoned. More important still, Shōkaku needed months of repair and Zuikaku had lost much of her air group, so neither could take part in the Battle of Midway a month later. Yorktown, by contrast, was hastily patched up in three days and played a crucial part there. In August the Allies opened the Guadalcanal campaign.

Admirals now fought at long range through scouting aircraft and radio, and mistaken identifications, bad weather and poor communication shaped events on both sides. The Japanese lost about 90 aircrew against 35 for the Americans, and Japan's highly trained carrier airmen proved impossible to replace, an attrition that helped turn the Second World War in the Pacific against it.

Our 1938 map shows the region before the war, and the 1945 map shows it at the war's end. Port Moresby is today the capital of Papua New Guinea.