 The object of the sortie was to attack Japanese transports at Kota Bharu, but in the afternoon of 9 December the Japanese submarine I-56 spotted the British ships, and in the evening they were detected by Japanese aerial reconnaissance. By this time it had been made clear that no RAF fighter support would be forthcoming. At midnight a signal was received that Japanese forces were landing at Kuantan in Malaya. Force Z was diverted to investigate. At 02: 11 on 10 December the force was again sighted by a Japanese submarine and at 08: 00 arrived off Kuantan, only to discover that the reported landings were a diversion.
