The South China Sea raid (designated Operation Gratitude) was an operation conducted by the United States Third Fleet between 10 and 20 January 1945 during the Pacific War of World War II. The raid was undertaken to support the liberation of Luzon in the Philippines, and targeted Japanese warships, supply convoys and aircraft in the region.
After attacking airfields and shipping at Formosa and Luzon, the Third Fleet entered the South China Sea during the night of 9–10 January. Aircraft flying from its aircraft carriers attacked Japanese shipping off French Indochina on 12 January, sinking 44 vessels. The fleet then sailed north and attacked Formosa again on 15 January. Further raids were conducted against Hong Kong, Canton, Hainan and Macau the next day. The Third Fleet departed the South China Sea on 20 January and, after making further attacks on Formosa and the Ryukyu Islands, returned to its base on 25 January.
The Third Fleet's operations in the South China Sea were highly successful. It destroyed many Japanese ships and aircraft, while losing relatively few of its own aircraft. Historians have judged the destruction of cargo vessels and oil tankers to have been the most important result of the raid, as these losses contributed to closing a supply route which was vital to the Japanese war effort. Subsequent attacks by Allied aircraft and warships forced the Japanese to cease sending ships into the South China Sea after March 1945.
Background
During 1941 and the first months of 1942, Japan conquered or established de facto rule over almost the entire South China Sea region. Control of the sea was vital to the Japanese economy and war effort, as it was the conduit through which essential supplies of oil and other natural resources passed from occupied Malaya, Borneo and the Dutch East Indies. The situation in French Indochina was particularly complex. After a short military confrontation in September 1940 the colonial government, which was loyal to the Vichy French collaborationist regime, permitted the Japanese to use ports and airfields in northern Indochina. In July 1941 the Japanese occupied southern Indochina and established airfields as well as an important naval base at Cam Ranh Bay. The French authorities remained in place as a puppet government. After the liberation of France in 1944, the colonial government sought to make contact with the new Free French government in Paris, and began preparations to stage an uprising against the Japanese. The Japanese also developed plans in 1944 to forcibly disarm the French forces and formally take over Indochina, and their intelligence services rapidly learned of the French authorities' intentions.
As the war turned against Japan, convoys of ships passing through the South China Sea frequently came under attack from Allied submarines and – by late 1944 – aircraft. These attacks were guided by information gained from signals intelligence and long-range air patrols, supplemented by reports from coast watchers along the Chinese coast and other observers in Asian ports. The United States Army Air Forces' (USAAF) Fourteenth Air Force, which was stationed in China, regularly attacked Japanese shipping in the South China Sea area. The command also made periodic attacks on Japanese-held ports in southern China and military installations in Indochina. The Allied clandestine services undertook few activities in Indochina until the second quarter of 1945.
While losses of oil tankers and freighters were increasingly heavy, the Japanese Government continued to order ships to make the voyage through the South China Sea. In an attempt to limit losses, convoys and individual ships took routes well away from the established sea lanes, or sailed close to the shore and operated only at night.
The United States began the liberation of the Philippines on 25 October 1944, with a landing at Leyte island in the central Philippines. After a base was established at Leyte, American forces landed at Mindoro island on 13 December. This operation was conducted to secure airfields that could be used to attack Japanese shipping in the South China Sea and support the largest element of the liberation of the Philippines, a landing at Lingayen Gulf in north-western Luzon that was scheduled for 9 January 1945. The Imperial Japanese Navy (IJN) suffered heavy losses in its attempt to attack the Allied fleet during the Battle of Leyte Gulf in October 1944 which, when combined with the losses during the Battle of the Philippine Sea in June 1944, left it unable to conduct further major battles. However, it remained capable of raiding Allied positions.
During late 1944 Admiral William Halsey Jr., the commander of the United States Third Fleet, sought to conduct a raid into the South China Sea and led the development of plans for such an operation. On 21 November he asked Admiral Chester W. Nimitz, the head of the United States Pacific Fleet, for permission to begin the attack but was turned down.
Preparations
In December 1944 the United States Navy's high command became concerned that the IJN would attempt to cut the supply line to the planned beachhead at Lingayen Gulf. On 26 December a Japanese naval force operating from Cam Ranh Bay shelled the Allied beachhead at Mindoro, but inflicted no damage. One of the Japanese destroyers involved in this operation was sunk, and all of the remaining ships were damaged by Allied air and naval attacks before returning to Cam Ranh Bay.
As further Japanese raids were expected, senior US Navy officers believed that it was necessary to destroy the IJN's remaining mobile forces, which were thought to be split between Cam Ranh Bay and the Inland Sea in Japan. At this time the Inland Sea was beyond the range of the USAAF's heavy bombers, meaning that an attack into the South China Sea was the only viable option for striking the IJN. The US Navy's intelligence service believed that the Japanese force based at Cam Ranh Bay was built around the two Ise-class battleships. Halsey and Nimitz discussed the proposed South China Sea raid during a meeting held around Christmas 1944 at the US Navy anchorage which had been established at Ulithi atoll in the Caroline Islands. On 28 December Nimitz gave Halsey permission to launch the attack once his fleet was no longer needed to directly support the Lingayen Gulf landings and "if major Japanese fleet units were sighted" in the area. Halsey issued the pre-prepared plans for the operation to his subordinates the same day. Its goals were to attack the Japanese fleet and shipping. In addition, the Americans believed that the presence of a powerful force in the South China Sea would discourage any further IJN operations in the area. While the Fourteenth Air Force was directed to attack Japanese shipping and airfields at Hong Kong in support of the invasion of Luzon, it was not informed of the plans for the Third Fleet to enter the South China Sea. The Fourteenth Air Force was also not briefed on the Fleet's operations during the South China Sea raid, and no attempts were made to coordinate the two forces' activities during this period.
The plans for the raid specified that the Third Fleet would enter the South China Sea via the Luzon Strait before proceeding south-west. The fleet's aircraft carriers would attack Japanese positions on Formosa, and provide support for the landings at Lingayen Gulf on 9 January. Three submarines from the Seventh Fleet were to take up station in the South China Sea to rescue the aircrew of any American aircraft which were forced to ditch. This plan would require the Third Fleet to operate near many Japanese airfields from which attacks could be mounted against the ships. Allied intelligence estimated that about 300 aircraft were usually stationed at Formosa; around 500 were in southern China and northern Indochina, a further 170 in southern Indochina, Burma and Thailand and 280 in the Dutch East Indies. While most of these were Imperial Japanese Army Air Force (IJAAF) aircraft, which were less effective against warships than IJN aircraft, there was a risk that kamikaze tactics would be employed. In addition, weather conditions were expected to be hazardous as the South China Sea is frequently affected by typhoons during January.
As of January 1945, the Third Fleet was built around the Fast Carrier Task Force, which was the main US Navy strike force in the Pacific. Control of this force alternated at regular intervals between the Third and Fifth Fleets (commanded by Halsey and Admiral Raymond A. Spruance respectively), with its designation also changing from Task Force 38 to Task Force 58. As Task Force 38 it was commanded by Vice Admiral John S. McCain Sr. In January 1945 Task Force 38 was organized into three fast carrier task groups and a night carrier group. The fast carrier groups were Task Group 38.1 with four aircraft carriers, two battleships, six cruisers and 25 destroyers; Task Group 38.2 with four carriers, three battleships, five cruisers and 24 destroyers; and Task Group 38.3, which comprised four carriers, three battleships, five cruisers and 17 destroyers. The night carrier group, Task Group 38.5, had two carriers and six destroyers, and operated with Task Group 38.2 during the day. These carrier groups embarked around 900 aircraft in total. The other major element of the fleet was a logistics force designated Task Group 30.8, which comprised a varying number of tankers and ammunition ships, several escort carriers transporting replacement aircraft for Task Force 38, and many escorting destroyers. In addition, the fleet was assigned an anti-submarine hunter-killer force designated Task Group 30.7, which comprised an escort carrier and three destroyer escorts and typically operated in support of Task Group 30.8.
Despite the American concerns, the IJN was not about to attack the Allied supply lines and Cam Ranh Bay was not a major fleet base. As of 1 January 1945, both the Ise-class battleships and the small number of other Japanese warships in the region were stationed at or near Singapore, and only escort vessels operated from Cam Ranh Bay. While large numbers of aircraft were located in Japanese-held territories bordering the South China Sea in January 1945, relatively few trained pilots were available to operate them. At this time the Imperial General Headquarters was considering a major offensive against the supply line to Lingayen Gulf, but on 20 January 1945 it decided to concentrate Japan's defensive efforts on the area around the home islands and only conduct delaying actions elsewhere. As a result, the Japanese forces in the South China Sea region at the time of the raid were focused on preparing to resist future Allied attacks. The Japanese believed that US forces could potentially land in Indochina once the liberation of the Philippines was complete, and were also concerned about possible attacks on the area by the British-led South East Asia Command. In an effort to better coordinate the Japanese forces in the South East Asia region, all Imperial Japanese Army and Navy units were placed under the overall control of the Southern Expeditionary Army Group in January 1945. This command was led by Gensui Count Hisaichi Terauchi from his headquarters in Singapore.
Despite these preparations, the Japanese remained unable to counter powerful attacks against shipping in the South China Sea. While the Navy's convoy escort forces had been expanded during 1944, they remained inadequate. The most common type of escort vessel, the Kaibōkan, was vulnerable to air attack as a result of their slow speed and weak anti-aircraft armament. The IJN also assigned few fighter aircraft to protect convoys in the South China Sea and, due to the interservice rivalry which badly hindered the Japanese war effort, rejected an offer from the Army to provide additional fighters for this purpose just before the Third Fleet's attacks on French Indochina.