USN aircraft engaged probably Japanese ship Kunikawa Maru according to the U.S. Joint Intelligence Committee. Daily summary dated 29 December 1941

An item reported that an US naval patrol aircraft sighted on 28 December at 17:30 PST on the location Latitude 28.13 North Longitude 125.46 West about 500 miles southwest of San Diego, USA a Japanese ship probably the Kunikawa Maru (478 feet long, 6,836 tons, around 20 knots speed). The ship opened fire. The J.I.C. referred to a radio station at Hellsboro, Oregon which reported a Japanese aircraft at the same position. Probably was she a supply vessel supporting the submarines off the US West Coast.

Source

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