The sinking of Shōhō

On 7 May 1942 both sides in the Coral Sea were searching for the enemy from dawn, and both got it wrong. The Japanese carriers sent their entire air group against two ships that a scout had taken for a carrier and a cruiser, but which were in fact the oiler Neosho and the destroyer Sims. The American carriers sent their air group against “two carriers” that existed only in a wrongly encoded report. The Americans, however, were in luck: on the way to the false target their airmen came upon the light carrier Shōhō and sank her in less than half an hour. She was the first Japanese carrier lost in the war. Lieutenant Commander Robert Dixon reported it by radio with the words “Scratch one flat top!”, which passed into US Navy history. After the loss of Shōhō Vice Admiral Shigeyoshi Inoue halted the convoy bound for Port Moresby.

Two days of blind man’s buff

Operation MO, by which the Japanese navy intended to capture Port Moresby in New Guinea, began on 3 May with the occupation of Tulagi in the Solomon Islands. The next day aircraft from the carrier Yorktown of Rear Admiral Frank Jack Fletcher attacked the ships in Tulagi harbour. From that moment both sides knew that an enemy carrier was somewhere in the Coral Sea, but neither knew where.

On the morning of 5 May Fletcher joined Rear Admiral Aubrey Fitch’s Task Force 11 with the carrier Lexington and the cruiser force of the Australian Rear Admiral John Crace, some 320 nautical miles south of Guadalcanal. Throughout that day and the next his ships took on fuel from the oiler Neosho. That same day fighters from Yorktown shot down a Japanese Kawanishi H6K flying boat that had approached the force. It did not manage to send a report, but when it failed to return to base the Japanese rightly guessed that it had fallen victim to carrier aircraft. Vice Admiral Takeo Takagi’s Japanese striking force, with the carriers Shōkaku and Zuikaku under the direct command of Rear Admiral Chūichi Hara, was meanwhile rounding the Solomons to the east and only entered the Coral Sea on the night of 5/6 May.

On 6 May fortune smiled first on the Japanese. At 10 a.m. a flying boat from the new base at Tulagi spotted Fletcher’s force and reported it. Takagi received the message in less than an hour, but his own ships were refuelling at the time, some 300 nautical miles north of the Americans, and the report suggested that the enemy was moving away to the south. Takagi sent both carriers with two destroyers under Hara south at 20 knots to be ready for battle at dawn. Hara found nothing and turned back in the evening. Meanwhile American bombers from Australia spotted Shōhō and the invasion convoy far to the north-west. Fletcher, convinced that the main Japanese carriers were still far away, near Bougainville, prepared to deal with the force covering the landing.

It is often written that on 5 and 6 May the two sides searched for each other in vain, although at one point they were less than a hundred miles apart. This agrees with historians’ findings, with one addition: the Japanese did find the Americans on 6 May but were unable to exploit it, and the opponents came closest to each other on the evening of that day. At about 8 p.m., according to post-war reconstructions, Hara’s and Fletcher’s carriers were only about 70 nautical miles, less than 130 kilometres, apart. Neither side knew it.

The Japanese mistake

On the evening of 6 May Fletcher sent Neosho, escorted by the destroyer Sims, south to a previously fixed rendezvous where the force was later to refuel again. It is often written that the oiler went off to refuel Sims in safer waters. In reality Neosho had already filled the tanks of Yorktown and the cruiser Astoria that day, and the destroyer was merely her escort. Fletcher himself headed north-west so as to be within range of the invasion convoy at dawn on 7 May. At 6.25 a.m. he detached Crace’s cruisers towards the Jomard Passage in the Louisiade Archipelago, through which the convoy was to pass on its way to Port Moresby.

At 7.22 a.m. a scout from Shōkaku reported American ships 163 miles south of the Japanese carriers, and at 7.45 a.m. specified that it could see a carrier, a cruiser and three destroyers. Hara, with Takagi’s consent, at once launched everything he had: 78 aircraft – 18 Mitsubishi A6M fighters, 36 Aichi D3A dive bombers and 24 Nakajima B5N torpedo bombers – under Lieutenant Commander Kakuichi Takahashi. A quarter of an hour or so later, seaplanes from Gotō’s cruisers reported an entirely different American force, with carriers, far to the west of Hara. The Japanese admirals had conflicting reports before them, but they did not recall the strike.

Takahashi’s aircraft reached the target at about 9.30 a.m. and for almost two hours circled the area searching for a carrier that was not there. When it was at last understood that there was only an oiler and a destroyer, the torpedo bombers and fighters turned back, and the 36 dive bombers fell on the two lone ships. Sims took three bombs, two of which exploded in the engine room; she broke in two and went to the bottom. Of nearly two hundred men in her crew, 14 or 15 survived, according to different accounts. Her captain, Lieutenant Commander Willford Hyman, was killed. Neosho received seven direct hits, and one of the damaged bombers crashed into her deck. The burning oiler, listing 30 degrees, did not sink, but in the confusion part of her crew took to rafts, which drifted away with the wind. Chief Watertender Oscar V. Peterson, badly burned while closing steam valves, died a few days later; he was posthumously awarded the Medal of Honor.

Neosho’s captain, Commander John S. Phillips, kept the wreck afloat for four days. Because of an error in calculating her position, help arrived only on 11 May: the destroyer Henley took off 123 survivors, including 14 from Sims, and sank the oiler by gunfire. Of some 68 men on the rafts, the destroyer Helm found only four on 16 May, one of whom soon died. According to Phillips’s report, of the 288 men aboard the oiler 20 were killed during the attack and 158 were listed as missing.

For the Japanese it was a costly mistake. All morning their main striking force was busy with auxiliary vessels, while Fletcher’s carriers, several hundred kilometres away to the north-west, had a free hand.

The American mistake

At dawn Fletcher sent out dive bombers from Yorktown to scout. At 8.15 a.m. one of them, Lieutenant John L. Nielsen, reported “two carriers and four heavy cruisers” north of Misima Island in the Louisiades. Fletcher concluded that he had found the enemy’s main force, and between 9.25 and 10.13 a.m. he launched 93 aircraft to attack: 18 Grumman F4F Wildcat fighters, 53 Douglas SBD Dauntless dive bombers and 22 Douglas TBD Devastator torpedo bombers. When Nielsen landed, it turned out that his report was wrong. He had seen cruisers and smaller ships, but the code card with which the pilot encoded his reports had been incorrectly arranged, and his message had come out with a completely different meaning. Fletcher is said to have exploded that the pilot had put the whole force in jeopardy. According to the popular version Nielsen had seen two cruisers and two destroyers; the confidential history of the battle issued by naval intelligence in 1943 speaks of two heavy and two light cruisers.

Rescue came from an unexpected quarter. Army bombers from Australia reported a carrier with escorts in the waters north of the Louisiades, not far from the position Nielsen had given. Fletcher, having nothing better, did not recall the strike and redirected it to the new target while it was still in the air. There the airmen found what they were looking for: Rear Admiral Aritomo Gotō’s covering force with the light carrier Shōhō. It has become accepted that the Americans stumbled on Shōhō by chance. Chance indeed played an enormous part, but in the end it was an army air force report that led them there.

“Scratch one flat top”

Shōhō was a small ship, converted from the submarine tender Tsurugizaki and in service as a carrier for only a few months. She had barely a dozen or so aircraft on board: eight Zero fighters, four older A5M fighters and six torpedo bombers. She was commanded by Captain Ishinosuke Izawa. Shortly before 11 a.m. the first aircraft of Lexington’s air group, led by Commander William Ault, broke through the few fighters and began bombing the carrier, which was manoeuvring desperately. She was hit by two half-ton bombs and five torpedoes. Moments later the aircraft from Yorktown arrived. According to their pilots the ship stopped manoeuvring and turned into the wind, perhaps to launch fighters, which made her a “perfect target”. The dive bombers hit her many more times, and the torpedo bombers finished her off at close range. According to post-war findings the ship received at least 13 bombs and 7 torpedoes in all.

At 11.31 a.m. Captain Izawa ordered the ship abandoned, and four minutes later Shōhō sank. She took most of her crew with her: of 834 men only 203 were saved, including her captain. The Americans lost three aircraft. At 12.10 p.m. Lieutenant Commander Robert E. Dixon, commander of Scouting Squadron 2 from Lexington, radioed his carrier: “Scratch one flat top! Signed Bob.” These words are sometimes described as a signal used for the first time in the US Navy. It was no regulation signal at all, but a pilot’s spontaneous remark which, thanks to the press, became one of the most famous quotations of the Pacific war.

Euphoria reigned on the decks of the American carriers. After five months of defeats, on the day the world was learning of the fall of Corregidor, the US Navy had sunk a Japanese carrier for the first time in the war. Fletcher nevertheless decided not to launch a second strike in the afternoon. He did not know where Shōkaku and Zuikaku were, and his force had in any case already been detected by Japanese seaplanes.

Inoue halts the convoy

The loss of Shōhō shook the command at Rabaul. The convoy carrying General Tomitarō Horii’s troops, which was to pass through the Jomard Passage and land near Port Moresby on 10 May, had lost its direct air cover, and at least two American carriers were operating nearby. Vice Admiral Inoue ordered the transports to turn back north and wait in the waters north of the Louisiades until Takagi’s carriers had destroyed the enemy. The landing that was to be the culmination of Operation MO was postponed. As it turned out, for good.

At the same time Crace’s cruisers arrived in the area of the Jomard Passage: the Australian HMAS Australia and Hobart and the American USS Chicago, with destroyers. Fletcher had sent them off without fighter cover to bar the convoy’s way if necessary, for which he has been criticised by historians. In the afternoon, at about 2.30 p.m., the force was attacked by 12 Mitsubishi G4M torpedo bombers and 19 Mitsubishi G3M bombers from Rabaul. Crace manoeuvred so skilfully that no ship was seriously hit, and the anti-aircraft guns shot down four bombers. The Japanese airmen reported sinking a California-class battleship and damaging a second battleship and a cruiser. Soon afterwards three American B-17 bombers from Australia bombed the force by mistake, fortunately without effect. The incident, for which the air forces under General Douglas MacArthur were responsible, was one of the first signs of how difficult cooperation between army aviation and the navy would be.

Hara’s evening strike

After the morning fiasco Takagi and Hara were determined to strike the American carriers that same day. They had only approximate reports of their position, and little time was left before dark. At 4.15 p.m. 12 dive bombers and 15 torpedo bombers took off, flown by the most experienced crews of both carriers, without fighter escort. The weather over the target was bad, and the Japanese aircraft passed the American force by. At 5.47 p.m. Fletcher’s radars detected them nearby, and the Wildcats went into the attack. They shot down seven torpedo bombers and one dive bomber for the loss of three of their own. The Japanese leaders ordered their men to jettison bombs and torpedoes and return.

The evening brought one of the strangest episodes of the naval war. At dusk, as Yorktown’s fighters were landing on, three aircraft with their lights on came over the force. Several Japanese pilots, lost in the darkness, had taken the American carrier for their own and tried to join the landing circuit. When they were recognised, the ships opened fire. Lexington’s radar later tracked strange aircraft circling about 30 miles to the east, evidently over a Japanese carrier. That night, then, the main forces of the two sides were much closer to each other than either admiral believed. Of the 27 aircraft of the evening strike, about 18 returned to the decks of Shōkaku and Zuikaku, lit up by searchlights. The loss of their best crews was felt keenly by the Japanese as early as the next day.

Place in the war

The sinking of Shōhō was the first major success of the US fleet in the Pacific war. The Japanese had lost their first carrier, and their offensive, which since December had run like clockwork from Hawaii to the Indian Ocean, was halted for the first time. The invasion convoy never reached Port Moresby. The battle was not over, however: the next day, 8 May, the carriers of both sides at last found each other and fought the first duel in history in which the ships never saw one another. In it the Americans lost the carrier Lexington, while the Japanese had the damaged Shōkaku and the aircraft-depleted Zuikaku put out of action for several months. Both were missing a month later at Midway, where Admiral Isoroku Yamamoto sent only Vice Admiral Chūichi Nagumo’s four carriers against the Americans. All four were sunk in the Battle of Midway.

The events of 7 May also showed how much the new naval warfare depended on reconnaissance. Both sides had powerful striking forces, and both wasted half the day on false targets. The outcome was decided neither by numerical superiority nor by better aircraft, but by accurate reports, the ability to assess them, and luck. The Americans, who thanks to broken codes knew more about the enemy’s intentions, drew their lessons faster. On 7 May the Japanese lost not only Shōhō but also several dozen experienced airmen, whom their naval air arm could no longer replace.