American submarines sinking Japanese ships in Philippine waters according to the U.S. Joint Intelligence Committee. Daily summary dated 29 December 1941

An item reported that US submarines sunk on 25 December a Japanese transport and on 27 December a supply ship in Philippine waters. Manila however could not longer be used as submarine operational base.

Source

Map Room Papers (Roosevelt Administration), 1942 - 1945. U.S. Joint Intelligence Committee. Daily summary No. 19 dated 29 December 1941