Most references date the Battle of the Coral Sea as starting on May 4, 1942 and lasting to May 8, 1942, but some move the starting date back to May 3, 1942 for reasons I hope to explain.
The Coral Sea is the body of the Pacific Ocean that lies off the eastern coast of Queensland, Australia and includes the famous Great Barrier Reef. It stretches north to Papua New Guinea, Solomon Islands and Solomon Sea. Its eastern boundary is marked by the islands of Vanuatu and New Caledonia. To the south by New Zealand and the Tasman Sea.
Strategically, whoever controls the Coral Sea would have easy access to strike the eastern half of Australia, where a large percentage of the population resides in cities like Cairns, Brisbane, Newcastle, Sydney and even the capital city of Canberra. It would also allow better access to launch air strikes against US controlled islands in southern and middle Pacific and to stop any further US expansion into the area.
In early 1942, Japan launched its plan to take control of strategic islands in the Coral Sea for the purpose of establishing air fields from which to launch attacks against Australia and US held islands further east and north. Their first targets were Port Moresby on the southern coast of Papua New Guinea and the island of Tulagi in the middle of the Solomon Islands. Allied forces learned of the plans.
On May 1, 1942, two US naval task forces were rendezvoused off Espiritu Santo, the main island of Vanuatu about 600 miles southeast of Tulagi and 1,400 miles east southeast of Port Moresby. Task Force 17 was led by Rear Admiral Frank Fletcher onboard the aircraft carrier USS Yorktown, which was escorted by 3 heavy cruisers and 6 destroyers. Task Force 11 was led by Rear Admiral Aubrey Fitch onboard the air craft carrier USS Lexington which was escorted by 2 heavy cruisers and 7 destroyers.
At the same time, Australian Task Force 44 left Sydney, led by Rear Admiral J.G. Crace, RN. His task force consisted of the heavy cruiser HMAS Australia and the light cruiser HMAS Hobart. The Australian task force would meet up with US carriers on May 4, 1942.
Also on May 1, 1942, US cruiser USS Chicago and destroyer USS Perkins, part of Task Force 44, headed north from Noumea, New Caledonia, about 500 miles south of Espiritu Santo, to join the US carriers.
On May 2, 1942, Task Force 17 and 11 split up. Fletcher’s Task Force 17 headed northwest to a position about 550 miles south of Guadalcanal. By May 3, 1942, Fletcher was only 110 miles away from Tulagi and the Japanese landing force.
On this day, May 3, 1942, a Japanese force arrived at Tulagi and began to unload supplies and equipment to build an airstrip. Fletcher’s Task Force 17 was within range of Tulagi. He launched carrier based planes to attack the Japanese at Tulagi. The US planes arrived and began their attack, sinking one destroyer along with some of the Japanese minesweepers and landing barges. Some historians believe that this attack on the Japanese landing force was the beginning of the Battle of the Coral Sea.
Over the next 5 days, the US and Australian fleets battled Japanese Vice Admirals Takeo Takagi and Shigeyoshi Inoue. The Japanese fleet consisted of the fleet carriers Shokaku and Zuikaku, the light carrier Shoho and 4 cruisers. Both sides launched air strikes against the opposing fleets which were never close enough to actually fire against each other.
On May 8, 1942, Inoue ordered the remaining Japanese ships to return to port, ending the Battle of the Coral Sea.
The US lost the USS Lexington after it was severely damaged. After the storage of air plane fuel exploded, the carrier was abandoned and sunk to avoid it falling into the hands of the Japanese. The USS Yorktown was also damaged but was able to continue back to Pearl Harbor where it was repaired and returned to battle. The US also lost the US destroyer USS Sims and severely crippled the oiler USS Neohsho, which eventually sunk. Sixty-nine US air craft was loss during the battle. Allied casualties amounted to 656 killed.
The Japanese lost the light carrier Shoho, 1 destroyer and 3 smaller warships. The Shokaku was heavily damaged but managed to return to port for repairs. Also damaged was a Japanese destroyer, 2 small warships and a transport. The Japanese lost 92 air planes and nearly 1,000 lives.
The Japanese losses at Coral Sea followed by constant Allied attacks and bombardment led the Japanese to abandon their air field at Port Moresby and slowed the Japanese expansion into the area. It was one of the first major victories for Allied forces, even though that victory came at a heavy cost.
The Battle of the Coral Sea was the first battle in history that was conducted solely by naval aircraft. It also demonstrated how important the air craft carriers were to the war effort over that of the battleships, changing the face of war for all time.
Sources for the above includes: The Battle of the Coral Sea Begins; Battle of the Coral Sea; World War II: Battle of the Coral Sea; Battle of the Coral Sea, 4-8 May 1942; Battle of the Coral Sea; The Battle of the Coral Sea; The Battle of the Coral Sea;