The Battle of Celebes Sea

The Battle of Celebes Sea was a major naval engagement between the Imperial Japanese Navy and a combined Naval fleet consisting of primarily British, German, and Dutch warships. The battle took place in the Celebes Sea around the Sulu Archipelago, and was the result of an attempted renewed Japanese naval invasion into Bormeo, a part of the ''Dutch East Indies. Numerous Japanese successes during the month of March in 1942, primarily victories in the Philippines and Burma, emboldened the Japanese to attempt and open the sea lanes to the central Dutch East Indies'' and make way for an invasion force. Japanese naval planning hinged on hoping that the French fleets were tied down in Indochina, that the Royal Dutch Navy was too spent, and that the Royal Navy was too tied down defending the Malaysian waters to successfully thwart a large naval operation in the Celebes Sea.

On March 14th, French surveillance aircraft operating out of the Philippines spotted the Japanese Fleet off the western coast of the Philippines. Notable amounts of transport ships and carriers were identified, and the Allied fleet was immediately notified and scrambled to intercept the Japanese force. The Allied fleet consisted primarily of British ships, including the two Fleet carriers HMS Indomitable and the ''HMS Formidable. The German light carrier SMS Graf Zeppelin and the battleships SMS Gneisenau and SMS Scharnhorst'' rounded out the fleet's capital ships. A mixed fleet of British, German, and Dutch cruisers and destroyers made up the rest of the bulk of the fleet. On the opposing side, the Japanese possessed the two modern fleet carriers Shokaku and Zuikaku, supported by the light carrier Shoho and a large complement of Cruisers and Destroyers.

The two forces officially engaged on March 16th as aircraft from both fleets intercepted each other over the south eastern waters of the Sulu Archipelago. A fierce dogfight between British Spitfires and German BF109's on one side and Japanese Zero's on the other was fierce and dozens of fighters were shot down during this first day of fighting. Both sides managed to sneak bombers to each others fleet, resulting in the Japanese light carrier Shoho being crucially damaged, while the Allied fleet was harassed, resulting in the loss of two destroyers and an oiler.

The next day, the Allied fleet was dealt a serious blow in the morning when Japanese bombers successfully hit the light carrier SMS Graf Zeppelin, rupturing parts of its hull and causing it to heavily tilt, rendering it unable to launch new aircraft. The Japanese also hit the Dutch cruiser HNLMS De Ruyter, which suffered a massive explosion when two bombs exploded in its magazine compartment, causing it to capsize very rapidly. The Japanese also managed to damage the fleet carrier HMS Indomitable by dropping bombs on its run deck, killing many of the crew and causing a deck fire. The Allied fleet immediately retaliated in kind and managed to sink a Japanese destroyer that was attempting to protect the heavily damaged light carrier Shoho, and then finished off the carrier by dropping a bomb on it that finally broke its back, causing it to sink rapidly. Several other small warships were sunk alongside, with damage down to a transport ship. In addition, German Stuka Dive Bombers managed to heavily damage the Fleet carrier Shokaku when they landed their bombs on top of several fully fuelled and loaded bombers attempting to take off, causing massive explosions on the carrier's deck, disfiguring many parts of the flight decks and causing a great loss of life.

By March 18th, both forces had begun to exhaust their air cover. Great loss of aircraft lowered the Japanese air capacity down to only 31 planes, down from 127, while the Allies were down to only 58 planes, down from 128, though most that remained were just fighters, most of the bombers having been lost on the 17th. Since the Allied fleet still possessed its two German battleships, which remained untouched by the air-fighting, the Japanese were now seriously outgunned should the two fleets happened to engage in surface combat. Both fleets disengaged by mid-day of March 18th, the Japanese fleet thwarted from its objective and the Allied fleet having taken great damage. The German light carrier SMS Graf Zeppelin, however, continued to tilt as the battle ended, it's hull breaches and fires barely contained from the damage it suffered the day before. British and Dutch sailors boarded the ship in a desperate attempt to help the German crew save the ship, the only carrier possessed by Germany. Nevertheless, the ship was beyond saving and its hull began to split as the engine room finally violently exploded. Its crew successfully abandoned ship as the carrier slowly capsized to the dismay of its German crew.

The Battle at the end of March 18th was a Japanese Strategic Victory, as the Japanese had sunk a light carrier, a cruiser, two destroyers, an oiler, and damaged a fleet carrier in exchange for just one Japanese light carrier, destroyer, and damage done to a fleet carrier. However, the battle was ultimately a tactical victory for the Allies as the Japanese fleet was thwarted from its main objective, the naval invasion of the Dutch East Indies. The loss of the SMS Graf Zeppelin, Germany's only aircraft carrier, however, was great blow to the morale of the ''German Pacific Navy. ''Damage done to the Allied fleet protecting the Dutch East Indies would take weeks and months to fully heal, preventing decisive Allied naval action against the Japanese navy for the next few months.