A quarter of an hour into the second dog watch on 24 April 1945, "Ralph Talbot" left the convoy to investigate a submarine contact. Three hours into the mid watch on 25 April, the convoy received a Commander Task Force 51 secret dispatch “warning of submarine activity in our immediate vicinity.” Ordered to divert from their present course and “to proceed via new reference points” to their destination, UOK 2 did so. "Ralph Talbot" rejoined the assemblage at the start of the second dog watch later that day. The warning may have been related to the activities of the Japanese submarine "RO-109", Lt. Nakagawa Hiroshi, which was sunk with all hands, 56 dead all told, by the high speed transport , that was escorting another Okinawa-bound convoy, after three attacks during the second dog watch on 25 April.