With Rear Adm. Fletcher’s Task Force 17 May 7, 1942

In the six months following Japan’s Decem­ber 7, 1941, attack on U.S. naval and air facil­i­ties at Pearl Harbor, Hawaii, the Jap­anese had the advan­tage of domi­nant air and naval power in the Pacific Ocean region. During these months the Japa­nese mili­tary looked to expand its con­quests beyond those coun­tries and Euro­pean colo­nial posses­sions already forced into Japan’s East Asia constel­la­tion—British Malaya, Thai­land, Burma, the Dutch East Indies (Indo­nesia), and the Amer­i­can posses­sion of the Philip­pines. Japa­nese con­trol over the Solo­mon Islands chain, for example, would have the benefit of effec­tively severing U.S. trans-Pacific transit to and from New Zea­land and Austra­lia, both coun­tries at war with Japan since Decem­ber 1941. Seizing the Austra­lian-admin­is­tered terri­tory on the large island of New Guinea, less than 100 miles north of the Austra­lian main­land, would give Japan naval and air bases at Port Moresby, the last bases between Austra­lia and Japan in hostile hands, thus conferring effec­tive domi­nance of the Coral Sea and virtu­ally all of Austra­lia’s northern and eastern coasts (see map below).

Fortunately for the Allies, U.S. cryptanalysts had deciphered Japa­nese naval mes­sages that clearly indi­cated the enemy intended to cap­ture Port Moresby and Tulagi in the southern Solomons in early May 1942. A formidable Japanese strike force of flattops, cruisers, and destoyers would cover the amphibious assault forces in an offensive the Japanese called Operation Mo (Mo Sakusen), short for Port Moresby Operation. Two U.S. carrier task forces and a joint U.S.-Australian cruiser force under U.S. Rear Adm. Frank J. Fletcher were dispatched to challenge the Japanese.

Beginning on this date, May 7, 1942, the carrier forces from each side engaged in air­strikes over two con­sec­u­tive days. On the first day U.S. carrier planes sank the Japa­nese light carrier Shōhō, which was covering the Port Moresby inva­sion force, while Japa­nese air­craft sank a U.S. destroyer. On May 8 carrier air­craft from both sides found the other’s fleet carriers, U.S. planes heavily damaging the Shōkaku and inflicting modest damage to the Zuikaku, while Japa­nese planes fatally damaged the USS Lexing­ton and severely damaged the York­town. After­wards the com­bat­ant forces disen­gaged and retired from the battle area. Because of a critical loss of carrier air cover, the Japa­nese recalled the Port Moresby inva­sion fleet on May 10.

In the wake of the Operation Mo setback, the Japa­nese Army com­menced in mid‑July 1942 an ulti­mately unsuc­cess­ful cam­paign to take Port Moresby with an over­land approach across the Owen Stanley Range via the Kokoda Track from Buna and Gona in Papua New Guinea. Over 6,250 Japa­nese soldiers lost their lives during the Kokoda Track Cam­paign. Japa­nese air group losses from losing the light carrier Shōhō and from damage sus­tained by the Shōkaku and Zui­kaku per­suaded the Japa­nese Navy to send the two fleet carriers back to Japan for replace­ment pilots and air­craft. The absence of all three Oper­a­tion Mo flat­tops the next month in the North Pacific con­trib­uted to the disastrous Japa­nese out­come in the Battle of Midway (June 4–7, 1942). The upshot of that four‑day naval engage­ment was the loss of four Japa­nese fleet carriers (the core of Japan’s naval offen­sive forces), 248 air­craft, and between 3,000‑plus and nearly 5,000 sailors and air­men (sources vary). The U.S. Navy’s vic­tory near Mid­way Atoll pre­cip­i­tated the sharp decline of Japan’s stra­tegic ini­tia­tive and naval supe­ri­ority in the Pacific Thea­ter. From 1943 on­ward, the Japa­nese neither con­quered nor kept another square inch of Pacific soil while their adversaries reaped the opposite returns.

Battle of the Coral Sea, May 7–10, 1942: First Carrier-to-Carrier Engagement

Battle of the Coral Sea: Japanese advances in the Southwest Pacific, 1942

Above: Reddish hashed areas in this map indicate where the Japa­nese had made advances in the South­west Pacific and South­east Asia areas between Decem­ber 1941 and April 1942. Port Moresby, the seat of Austra­lian-admin­is­tered New Guinea, lies on the island’s “tail” where the broken-line arrow points left and up­ward (center right in map). The words Coral Sea can be seen under the longer left-facing broken-line arrow pointed at the north­eastern coast of Austra­lia. The Solo­mon Islands lie to the left of the broken-line “lobster tail” arrow and north of the lobster’s two arms. Seizing Port Moresby and a series of other islands and ports, including Tulagi in the Solo­mons, would strengthen Japan’s southern defen­sive screen, further iso­late Austra­lia, and bring immense bene­fits to securing Japan’s earlier expan­sion in South­east Asia and the South­west Pacific. On May 10, 1942, the Japa­nese abruptly called off their sea­borne inva­sion of Port Moresby, the oper­a­tion that had initiated the pivotal naval Battle of the Coral Sea.

Battle of the Coral Sea: Japanese carrier Shōhō under attack, May 7, 1942Battle of the Coral Sea: USS Lexington burning and abandoned, May 8, 1942

Left: Japanese light carrier Shōhō under attack by U.S. Navy planes on May 7, 1942, during the Battle of the Coral Sea. Nine bomb hits and four torpe­does from U.S. carriers York­town and Lexing­ton sank the Shōhō within five minutes after the first blow was scored. The Shōhō, with a com­ple­ment of 785 offi­cers and men and 30 air­craft, was on her first com­bat oper­a­tion and was the first Japa­nese air­craft carrier to be sunk during World War II. Too dif­fi­cult to distin­guish in the lower center of the photo­graph is a Douglas TBD Devas­tator, a U.S. torpedo bomber. Two or three other U.S. Navy air­craft are visi­ble above the burning carrier. The photo­graph was taken by the air­crew of a U.S. Navy torpedo bomber from the Yorktown.

Right: U.S. fleet carrier Lexington burning after her crew aban­doned ship during the Battle of the Coral Sea, May 8, 1942. Some 216 crew­men were killed and 2,735 evacuated. The “Lady Lex” sus­tained numer­ous hits from Japa­nese carrier air­craft. How­ever, it was a series of mas­sive explo­sions ini­tially set off by sparks from electric motors that ignited gaso­line vapors from ruptured fuel tanks that proved fatal to the flat­top. Lexing­ton’s surviving crew members were rescued. The val­iant lady and the dead were sent to the ocean floor after Rear Adm. Fletcher ordered a U.S. destroyer to torpedo the flaming wreck.

Battle of the Coral Sea 1942: First Aircraft Carrier Battle in History