|Battle of the Coral Sea|
|Carrier battle, first day|
|Carrier battle, second day|
|Recovery, reassessment and retreat|
A new type of naval warfare
The experienced Japanese carrier aircrews performed better than the US, achieving greater results with an equivalent number of aircraft. The Japanese attack on the American carriers on May 8 was better coordinated than the US attack on the Japanese carriers. The Japanese suffered much higher losses to their carrier aircrews, however, losing 90 killed in the battle compared with 35 for the Americans. Japan's cadre of highly-skilled carrier aircrews with which it began the war were, in effect, irreplaceable because of an institutionalized limitation in its training programs and a complete absence of a pool of experienced reserves. Coral Sea started a trend which would result in the irrepairable decimation of Japan's veteran carrier aircrews by the end of October 1942.
While the Americans did not perform as expected, they did learn from their mistakes in the battle and made improvements to their carrier tactics and equipment, including fighter tactics, attack coordination, and defensive strategies, which contributed to better results in later battles. Radar gave the Americans a limited advantage in this battle, but its value to the US Navy would increase over time as the technology improved and the Allies learned how to employ it more effectively. Also, following the loss of Lexington, improved methods for containing aviation fuel and better damage control procedures were implemented by the Americans.
Japanese and US carriers would face off against each other again in the battles of Midway, Eastern Solomons, and Santa Cruz Islands in 1942, and the Philippine Sea in 1944. Each of these battles was strategically significant in deciding the course and ultimate outcome of the Pacific War.
Tactical and Strategic Implications
In terms of ships lost, the Japanese won a tactical victory by sinking an American fleet carrier and an oiler, both strategic assets, as well as a destroyer (41,826 tons) versus a light carrier, a destroyer, and several smaller warships (19,000 tons) sunk by the Americans. Lexington represented, at that time, one quarter of US carrier strength in the Pacific. The Allies did achieve their first significant Japanese warship kill in the Pacific by sinking Shoho, while also severely damaging Shōkaku and putting her out of action for months of repair.
In contrast to the strenuous efforts by the Americans to employ the maximum forces available for Midway, the Japanese apparently did not even consider trying to include Zuikaku in the operation. No effort appears to have been made to combine the surviving Shōkaku aircrews with Zuikaku's air groups and to quickly provide Zuikaku with replacement aircraft so that she could participate with the rest of the Combined Fleet at Midway. Shōkaku herself was unable to conduct further aircraft operations, with her flight deck heavily damaged, and she required months of repair in Japan.
Furthermore, Yamamoto apparently missed the other implications of the Coral Sea battle, which were that the American carriers had appeared unexpectedly in exactly the right location at the right time to effectively contest the Japanese plans and that the US Navy carrier aircrews had attacked with sufficient skill and determination to do serious damage to the Japanese carrier forces. In the subsequent battle at Midway, Japan lost four carriers, the core of its naval offensive forces, and thereby lost the strategic initiative in the Pacific War.
Situation in the South Pacific
The failure to land troops at Port Moresby forced Japan to fight a land campaign in New Guinea. The Japanese military was unable to support land operations so far from its industrial base in Japan. The planned invasion of Fiji, Samoa and New Caledonia was also deferred and was canceled after Midway.
At the time Australians and the U.S. forces in Australia were disappointed with the outcome of the Battle of the Coral Sea. It was feared that the operation was the precursor to an invasion of the Australian mainland and that the check Japan had received would only be temporary. In a meeting held in late May the Australian Advisory War Council described the battle's result as being "rather disappointing" given that the Allies had advance notice of Japanese intentions. General MacArthur also provided Australian Prime Minister John Curtin with a military appreciation stating that "all the elements that have produced disaster in the Western Pacific since the beginning of the war" were still present as Japanese forces could strike anywhere if supported by major elements of the IJN.