May 7th 1942 , Battle of Coral Sea
The Battle of the Coral Sea, fought from May 4th-8th, 1942, was the first naval engagement in history where the opposing ships neither saw nor directly fired on each other. It also marked the end of Allied defensive-only activity, and paved the way for future Allied offensive operations.
This was the first of six battles between opposing aircraft carrier forces during the war. This battle resulted from American and Australian naval and air forces thwarting a Japanese amphibious operation intended to capture Port Moresby in New Guinea. A Japanese air base there would have threatened northeastern Australia and strategic sea lanes, possibly forcing Australia out of the war and certainly enhancing the strategic defenses of Japan's oceanic empire and further Japanese expansion into the Pacific.
The Japanese scored a tactical victory by sinking the aircraft carrier USS Lexington, heavily damaging the carrier USS Yorktown, and sinking a destroyer and an oiler. Against those losses, the Americans managed to achieve their first substantial kills against the Japanese Navy by sinking the light carrier Shoho and severely damaging the Shokaku, as well as damaging other smaller ships.
In truth the battle was an operational and strategic defeat for the Japanese--the first major check on their offensive sweep begun five months earlier at Pearl Harbor.
First, the invasion of Port Moresby was thwarted, boosting Allied chances in the bitterly fought New Guinea campaign, and fending off a threat to the supply lines running between the US and Australia. Second, the Japanese were denied the services of their two newest carriers on the eve of the Battle of Midway a month later. Historians have argued whether these two Japanese carriers would have actually been used at Midway; regardless, had these two carriers been available at Midway, things might well have turned out very differently for the Americans.
Elsewhere in the war
To put the importance and timing of this battle in context, we need to take a quick look at what else was happening in late April - early June 1942.
April 23rd was the beginning of the Luftwaffe's air attacks against the British cathedral cities.
On May 1st, General Carl Spaatz was designated commander of the Eighth Air Force, which had not yet left for England and was still Stateside at Bolling Field, Washington, DC.
On May 4th, US Navy aircraft attacked the Japanese invasion fleet at Tulagi Island, the first shots in what developed into the Battle of the Coral Sea.
Corregidor Island in the Philippines surrendered to the Japanese invaders on May 6th, ending US resistance in the Philippines.
May 7th marked the sinking of the Japanese light carrier Shoho by US Navy dive bombers, while the Japanese sank a US oiler and destroyer, mistaking them for a US carrier and cruiser. US Army Air Force bombers mistakenly attacked US ships, but caused no damage. During the day, the Japanese invasion force headed for Port Moresby turned back towards Rabaul.
May 8th was the day the US Navy lost the USS Lexington
May 8th was also the day the Germans began their Crimean offensive in Russia.
It was not until five days after the end of Coral Sea combat that the first 8th Air Force bomber squadron, minus its aircraft, reached England (May 13th).
June 4th-7th was the pivotal Battle of Midway, which truly turned the tide of the war in the Pacific.
The forces involved and the timeline
The Japanese campaign included two seaborne invasion forces, the main one aimed at Port Moresby, and a smaller one targeting Tulagi, in the Southern Solomons. These would be supported by Japanese land-based airpower from bases to the north and by two naval forces containing a small aircraft carrier, several cruisers, seaplane tenders and gunboats. Simultaneously, a powerful screening force built around the big carriers Shokaku and Zuikaku sortied from Truk to prevent interference from any Allied naval forces that might be in the area.
The U.S. Navy, tipped off to the enemy plans by superior communications intelligence and codebreaking, countered with two of its own carriers, plus cruisers (including two Australian cruisers), destroyers, submarines, land-based bombers and patrol seaplanes.
Sunday, May 3rd, 1942
On May 3rd, the smaller of the two Japanese naval forces made an unopposed landing at Tulagi in the southern Solomons. The small force of Australian commandos and airmen who had garrisoned Tulagi evacuated the previous day, having been notified by coastwatchers that the Japanese were en route.
While Tulagi was being occupied, the main force of the Japanese Fourth Fleet was completing its final preparations for the amphibious invasion of Port Moresby, which was scheduled to start on May 10th.
Monday, May 4th, 1942
The USS Yorktown, which had been refueling at Espiritu Santo, ran north and launched three air strikes against the Japanese shipping in Tulagi Harbor, hitting a destroyer and several small boats. It then returned southward to rejoin the Lexington.
Yorktown SBD aircraft return to their carrier after striking Japanese shipping in Tulagi harbor. Koei Maru is straddled by bombs while at anchor in Tulagi harbor during the attacks by Yorktown aircraft.
Meanwhile, long range, land-based bombers from General MacArthur's SWPA command were combing the seas for the Japanese convoy approaching Port Moresby, but failed to locate it either that day or the next.
Tuesday, May 5th, 1942
Allied intelligence reported that Port Moresby was the main enemy objective and that landings could be expected any time between May 5th and May 10th. B-17s and B-26s of the SWPA stood by for an attack order, while other planes carried out neutralizing raids to keep Japanese land-based air power from participating in the coming battle.
Wednesday, May 6th, 1942
It was not until late on the 6th, however, that three AAF B-17s finally located the Japanese invasion force headed for the Jomard Passage and the Louisiade Islands. US Rear Admiral Frank "Jack" Fletcher, Commander of the Allied Fleet, dispatched a group of cruisers and destroyers to cover the Jomard Passage, and moved north with his carrier force to contact and close with the main enemy fleet.
Thursday, May 7th, 1942
SBD-3, LTJG William E. Hall, VS-2, USS Lexington
Battle of the Coral Sea, May 7th-8th, 1942
The opposing commanders, Admiral Fletcher and Japanese Vice Admiral Takeo Takagi and Rear Admiral Tadaichi Hara, endeavored to strike the first blow, an essential tactic for victory (and survival) in a battle between heavily-armed and lightly-protected aircraft carriers.
However, both sides suffered from inadequate efforts by their scouts and launched massive air strikes that sank relatively unimportant secondary targets, while leaving the most important enemy forces untouched.
That morning, American scout planes reported sighting an enemy carrier, which proved to be the Shoho, and four heavy cruisers off Misima Island. Unfortunately, they were misreported as "two carriers and four heavy cruisers".