Large Japanese naval force gathered north of the Bonin Islands according to the U.S. Joint Intelligence Committee. Daily summary dated 14 March 1942

An item reported that a large amount of Japanese warships was ordered to gather for the period 13-23 March on a position not far from the north of the Bonin Islands. The force was to consist of 5 battleships, 4 aircraft carriers, 2-4 heavy cruisers, 1 light cruiser, 28 destroyers and 7 submarines and probably 12-15 armed merchantmen. The force was believed to be responsible for the defence of Japan and similar to the earlier reported screening force although now somewhat enlarged.

Source

Map Room Papers (Roosevelt Administration), 1942 - 1945. U.S. Joint Intelligence Committee. Daily summary No. 94 dated 14 March 1942.