The Japanese on Tulagi

On the morning of 3 May 1942 Japanese warships under Rear Admiral Kiyohide Shima entered the bay between the island of Tulagi and the islets of Gavutu and Tanambogo in the Solomon Islands and put some 400 naval infantry ashore. Nobody fired at them. The small Australian garrison had sailed away a few hours earlier, and the capital of the British protectorate stood empty. The landing opened Operation MO, the great Japanese plan to seize Port Moresby in New Guinea, and became the first act of the Battle of the Coral Sea. The next day, 4 May, aircraft from the American carrier Yorktown appeared over Tulagi. It was the first blow of the battle and at the same time a sign that the Americans knew far more about Japanese intentions than the command in Rabaul supposed.

Operation MO

After taking Rabaul in January and landing at Lae and Salamaua in March 1942, the Japanese navy wanted to close the ring around its new base on New Britain. Vice Admiral Shigeyoshi Inoue, commander of the 4th Fleet at Rabaul, regarded Port Moresby, the capital of Australian Papua on the south coast of New Guinea, as the most important objective. From there Allied bombers could reach Rabaul and Lae; in Japanese hands the town would give their aircraft reach over the whole of the Coral Sea and north-eastern Australia. The second objective was Tulagi, where Inoue wanted to set up a seaplane base. Flying boats from Tulagi were to patrol the eastern Coral Sea and cover the flank of the whole operation and, in the longer term, support an expedition against New Caledonia, Fiji and Samoa, which in the plans agreed in March and April was to cut Australia off from the United States.

The plan was elaborate, like most Japanese plans of the period. Shima’s force was to take Tulagi on 3 May. Rear Admiral Sadamichi Kajioka’s invasion force, with eleven transports carrying the army troops of General Tomitarō Horii and a naval infantry battalion, was to leave Rabaul on 4 May, round the eastern tip of New Guinea through the Louisiade Archipelago and land near Port Moresby on 10 May. Close cover was provided by Rear Admiral Aritomo Gotō’s force with the light carrier Shōhō and four heavy cruisers. Once the operation was over, in mid-May, other units were to seize the islands of Nauru and Ocean (Banaba) with their phosphate deposits; this part of the plan was called Operation RY.

After the March raid by American carriers on Lae and Salamaua, however, Inoue was unwilling to act without strong air cover. Admiral Isoroku Yamamoto’s Combined Fleet assigned him the striking force of Vice Admiral Takeo Takagi, with the two large carriers of Rear Admiral Chūichi Hara’s 5th Carrier Division, Shōkaku and Zuikaku, two heavy cruisers and six destroyers. These were ships that had struck Pearl Harbor in December and taken part in the raid into the Indian Ocean in April. Takagi’s force left Truk on 1 May and was to sweep round the Solomons to the east, enter the Coral Sea from the open ocean and destroy any Allied force that tried to interfere with the landing. On the way the carriers were also to deliver nine fighters to Rabaul. Two attempts, on 2 and 3 May, were frustrated by the weather, one fighter came down in the sea, and the whole roundabout venture cost the force two days.

The Americans read the codes

The Japanese command did not know that its intentions had been no secret for several weeks. Since the beginning of 1942 the US Navy had been breaking an ever larger part of the Japanese fleet’s operational code, which the Americans called JN-25. In April the cryptanalysts of Station Hypo at Pearl Harbor, headed by Commander Joseph Rochefort, and of the unit in Melbourne, formed by men evacuated from Corregidor by submarine and later named FRUMEL, were already reading a substantial part of the radio traffic. The intercepted messages showed that carriers were gathering at Rabaul, that the operation bore the code name MO and that its target was most probably Port Moresby, with a date at the beginning of May. The British helped too: in mid-April they read a message assigning Shōkaku and Zuikaku to Inoue.

The commander of the Pacific Fleet, Admiral Chester Nimitz, decided to take up the challenge. He sent two forces to the Coral Sea: Rear Admiral Frank Jack Fletcher’s Task Force 17 with the carrier Yorktown, and Rear Admiral Aubrey Fitch’s Task Force 11 with the carrier Lexington. They were to be joined by a cruiser force under the Australian Rear Admiral John Crace. The Pacific Fleet’s other two carriers, Enterprise and Hornet, had just returned from the Doolittle Raid and could not arrive in time. On 1 May Fletcher’s and Fitch’s forces met a few hundred miles north-west of New Caledonia and began to refuel.

The evacuation of Tulagi

Tulagi, a tiny island off the south shore of the Nggela Islands, known to Europeans as the Florida Islands, had been the seat of the British Resident Commissioner since the end of the 19th century. It had a good, sheltered anchorage, and on neighbouring Gavutu the Australian air force had set up a forward base for Catalina flying boats. Since January it had been bombed regularly by Japanese aircraft from Rabaul, and most of the civilians had been evacuated as early as February. Fewer than fifty servicemen remained: 24 commandos of the Australian 2/1st Independent Company under Captain A. L. Goode and about 25 men of No. 11 Squadron of the Royal Australian Air Force who ran the base. They had no chance of holding it and knew it. An evacuation plan had long existed, and the flying boats had been withdrawn from Gavutu before the end of April.

It is sometimes recorded under 2 May that the garrison was evacuated in response to a warning from American radio intercepts. That is a simplification. Signals intelligence had forewarned the Allied command of Operation MO and of Tulagi being one of its objectives, but the immediate signal to withdraw came from the coastwatchers. On 2 May Jack Read, hidden in the mountains of Bougainville, reported that a large force of Japanese ships had left the Buka area, and later that day Donald Kennedy on New Georgia reported Japanese ships heading south towards the central part of the archipelago. Goode and the airmen’s commander, Flight Lieutenant R. B. Peagam, decided it was time to go. Still on 2 May they began destroying equipment, fuel and the base installations, and early on the morning of 3 May they sailed in two small vessels for Vila in the New Hebrides. The boat carrying the airmen spent the day off the coast of Guadalcanal, with the district officer and coastwatcher Martin Clemens, and continued its journey only after dark.

Shima’s landing

Shima’s force was modest. It consisted of two minelayers, the flagship Okinoshima and Kōei Maru, the destroyers Kikuzuki and Yūzuki, several minesweepers and submarine chasers, and the transport Azumasan Maru carrying some 400 troops, mainly of the Kure 3rd Special Naval Landing Force. Gotō’s force with Shōhō covered it from a distance. On the morning of 3 May the troops went down into landing barges and occupied Tulagi, Gavutu and Tanambogo without firing a shot. They set to work building the base at once, and that same day six seaplanes alighted in the anchorage. Inoue could consider that the first stage of Operation MO had gone without a hitch. Gotō’s force turned back north to cover the invasion convoy, which was leaving Rabaul the next day.

The strike from Yorktown

At 5 p.m. on 3 May Fletcher received word that the Japanese force heading for Tulagi had been sighted the previous day. He was then several hundred miles to the south. Lexington was still refuelling and was not due to join him for another two days. Fletcher did not want to miss the opportunity. He broke off refuelling, left Fitch and the oiler behind and, with Yorktown alone and her cruisers and destroyers, steamed north through the night at 27 knots towards Guadalcanal. At dawn on 4 May he was about 160 kilometres south of Tulagi, hidden from the enemy’s eyes by a belt of cloud.

At 7.01 a.m. 28 Douglas SBD Dauntless dive bombers and 12 Douglas TBD Devastator torpedo bombers took off from her deck. The fighters stayed over the carrier. At about 8.50 a.m. the first bombers dived on the ships lying at anchor off Tulagi and Gavutu. The Japanese were completely surprised: they had no fighters there, and their seaplanes were only just being deployed. Bombs and torpedoes hit the destroyer Kikuzuki and badly damaged Okinoshima. At noon a second wave arrived and caught the ships fleeing from the bay north-east of Savo Island. It sank two minesweepers and badly damaged the auxiliary minesweeper Tama Maru. Its four escorting Grumman F4F Wildcat fighters shot down several seaplanes and strafed the destroyer Yūzuki, killing her captain and nine sailors. A third, smaller wave in the afternoon further damaged Azumasan Maru and hit Okinoshima again.

The American airmen returned convinced that they had won a great victory. Their reports, later incorporated into the confidential history of the battle issued by naval intelligence in 1943, recorded the sinking of two destroyers, a freighter and four gunboats and damage to a light cruiser that was said to have beached itself. The reality was more modest. Kikuzuki did indeed run aground off Gavutu, and on 5 May she slid into the water and sank. Two small minesweepers went to the bottom, and Tama Maru sank two days later. According to Japanese figures the raids killed 87 sailors, and 36 men of the landing force were seriously wounded. The remaining ships, including the damaged Okinoshima, withdrew to Rabaul, and the seaplane base began operating. The Americans lost one torpedo bomber, whose crew ditched and were rescued, and two fighters that lost their way and crashed on the south coast of Guadalcanal; both pilots were picked up by the destroyer Hammann.

Admiral Nimitz judged the results soberly. Twenty-two torpedoes and 76 half-ton bombs had produced few hits, which in his comment showed how quickly in wartime the skill of aircrews deprived of regular training declines. Something else, however, mattered more: the strike had betrayed the presence of an American carrier in the Coral Sea. Takagi, who after the failed fighter delivery was still far to the north, raced south at high speed but was too late to catch anyone. Fletcher turned back to meet Fitch and Crace, a rendezvous made on the morning of 5 May. Both sides began searching for each other.

Place in the war

The landing on Tulagi was the easiest part of Operation MO and the only one that succeeded. Over the following days the Coral Sea saw the first carrier battle in history, in which the Japanese lost the light carrier Shōhō and the Americans Lexington. Inoue called off the seaborne expedition against Port Moresby, and it was the first Japanese operation of the war that failed to achieve its objective. Operation RY failed too: on 11 May the American submarine S-42 sank Okinoshima near Buka, and the Japanese did not take Nauru and Ocean Island until August. Rear Admiral Shima appeared once more in the great history of the war in October 1944, when his cruiser force entered the Surigao Strait too late during the Battle of Leyte Gulf.

Tulagi, by contrast, remained in Japanese hands and became the key to what followed. Seaplanes from Tulagi patrolled the Coral Sea, and at the beginning of July the Japanese began building an airfield on the plain by the Lunga River on neighbouring Guadalcanal, from which their bombers could reach the New Hebrides and New Caledonia. On 7 August 1942 the US Marines landed simultaneously on Guadalcanal and on Tulagi, Gavutu and Tanambogo. The garrisons of the islets, which included men of the unit that had taken them on 3 May, fought almost to the last man. So began the six-month Guadalcanal campaign, in which the Japanese navy and air arm suffered losses they could never make good. The capture of a small, empty island, which on 3 May had looked like a routine operation, thus set off a chain of events leading to one of the turning points of the war in the Pacific.

The Tulagi episode also showed two things that decided the course of the war in the months that followed. The first was intelligence: both the broken codes and the coastwatcher network gave the Allies knowledge of enemy movements that the Japanese lacked. The second was the role of carriers, which could appear out of nowhere and strike hundreds of kilometres from where anyone expected them.