Enemy submarine activities off American Pacific coast decreasing according to the U.S. Joint Intelligence Committee. Daily summary dated 6 January 1942

An item reported that the enemy submarine activities off the American Pacific coastline decreased. One unknown submarine was on 4 January sighted in the vicinity of the mouth of the Gulf of Dulce, Costa Rica about 300 miles west of Balboa.

Source

Map Room Papers (Roosevelt Administration), 1942 - 1945. U.S. Joint Intelligence Committee. Daily summary No. 27 dated 6 January 1942