Japanese navy continued with her activities in the Truk-New Britain area according to the U.S. Joint Intelligence Committee. Daily summary dated 29 April 1942

An item reported that the Japanese navy continued with her activities in the Truk-New Britain area. The fact that Japanese ships moved southward from Truk was probably due to the rising Allied threat in stead off a planned offensive. Continiously Allied air attacks and posssible task forces were a complicated factor for the Japanese navy in executing planned operations. On the other hand seemed the Japanese navy to gain air and surface supremacy.

Source

Map Room Papers (Roosevelt Administration)