Dauntless dive bombers over Truk 1944. (National Archives)
During years prior to World War II Japanese Imperial Forces had built up numerous strongholds and bases throughout the Pacific islands chains. Truk Lagoon was one of the biggest of these and had been transformed into a huge naval support and supply center. It was known as the "Gibraltar of the Pacific."
Naval Operations from 1942 to 1944 under Admiral Spruance. ("Hailstone"-Lindemann)
The overall American strategy in the Pacific called "island hopping", was to isolate and cut off specific Japanese bases that could be easily overcome, while bypassing the stronger ones. Once the Japanese supply lines had been disrupted, the weakened strongholds, previously bypassed could be taken if necessary.
Admiral Spruance the theater commander, was executing this strategy by directing various strike operations throughout the various Pacific island chains. As part of this he dispatched Rear Admiral Mitscher and Task Force 58 to conduct raids throughout the Caroline islands. The task force consisted of the carriers USS Essex, USS Bunker Hill, USS Yorktown and USS Enterprise. There were also several light carriers, battleships, including the USS New Jersey and USS Iowa, cruisers and destroyers assigned to the task force.
On February 4, 1944 an American B-24 made a reconnaissance flight over Truk alerting Japanese Forces that an attack was eminent. Truk’s commander Admiral Koga ordered the warships anchored there to sail for safer waters. When the first wave of American carrier planes descended on Truk, on February 16, 1944 all that remained were supply vessels and small combatant ships. During two days of air strikes, American carrier based aircraft of sank ten warships and thirty-one transport ships. Unfortunately none of the Japanese Navy’s major capital ships were caught in the lagoon. Further, in addition to the severe damage Truk’s shore facilities took, the Japanese lost seventy aircraft in aerial combat and another two hundred on the ground.
Track of Task Group 50.9 as they conducted raids on Truk Naval Base. ("Hailstone"-Lindemann)
American surface and submarine forces also engaged Japanese shipping trying to escape Truk and sunk more ships. U.S. losses were less than twenty aircraft and damage to the carrier Intrepid.