Truk's history of early Spanish domination was followed by German acquisition after the Spanish-American war about 1890, and then a Japanese mandate from the League of Nations upon Germany's defeat in 1918.
The Japanese era saw a great buildup of arms and bases in advance of a wide military blitz over the Western Pacific. The blitz was supplied heavily from facilities at Truk, where often more than 1,000 merchant and war ships moored in readiness for further deployment.
Five airfields supporting close to 500 aircraft provided complete protection over Truk's Gibraltar-like facilities. A deep lagoon, high islands and circling barrier reef provided extensive natural protection.
Patrol boats, torpedo boats, submarines, tugs, landing craft, gunboats and mine sweepers contributed to the final defenses and service needs to maintain this big base.
Truk was considered the most formidable of all Japanese strongholds in the Pacific. This reputation caused an overconfident Truk command to relax their vigil against invasion, in spite of U.S. forces fast approaching from the East. Supplies from Japan had almost ceased, due to immense
successes of U.S. submarines finally equipped with torpedoes that found their mark. Supply convoys receiving nearly 90% losses enroute to Truk, deprived the garrison of food, fuel and new armaments desperately required to maintain strength.
By early 1944, U.S. forces had amassed a huge armada of top line carriers, battleships, cruisers, destroyers and submarines for a major surprise sweep against Truk on February 16th, 17th and 18th. This attack, coded "Operation Hailstone", caught the Japanese totally unaware, and led to one of the most successful U.S. engagements of WWII.
After a follow up attack in April, 1944, Truk was reduced to rubble with over 70 shipwrecks, 400 aircraft destroyed or sunk, and the menace of this big fortress removed forever.
U.S. forces declined engagement with the 40,000 troops at Truk, and after these attacks, starvation consumed many of the defenders before the eventual surrender of Japan late in 1945.
About 20 years later, adventure divers such as Jacques Cousteau, Al Giddings and Klaus Lindemann discovered the wonders of this huge sunken fleet, replete with incredible vistas of war machinery, soft coral draperies, fish life and personal mementos.
Truk is without parallel-its ghostly remains create the world's greatest wreck diving in a wonderfully comfortable location.