Several Japanese ships sighted during Allied air attack on Rabaul according to the U.S. Joint Intelligence Committee. Daily summary dated 15 March 1942

An item reported that during an attack on the Vunakanau airdrome at Rabaul [New Britain, Papua New Guinea] an Allied B-017 sighted a large transport, 3 cruisers and 10 smaller ships (some probably destroyers) of the Japanese.

Source

Map Room Papers (Roosevelt Administration), 1942 - 1945. U.S. Joint Intelligence Committee. Daily summary No. 95 dated 15 March 1942.