On February 4, 1944, two PB4Y reconnaissance aircraft were dispatched to gather photographic intelligence of the Japanese military installations at Truk. The atoll had been a part of the Japanese Empire since World War I and closed to foreigners. Therefore the only information the war planners had about the base was either obsloete or hearsay data from POW interrogations. Obviously, more had to be known about the enemy before an attack could be launched, and the recently conquered airstrips in the Marshalls were now within range of the PB4Ys.
The planes were intercepted over their targets in Truk but were able to gather some important intelligence and return safely. Truk was being used as the foreward anchorage of the Imperial Fleet and several capital warships could be seen in the lagoon. The super battleship Musashi was there as the Second Fleet's flagship, and there were also carriers, cruisers, destroyers and submarines on the film. Several airfields and hundreds of aircraft were based in Truk as well. Without a doubt, Truk would be costly to destroy.