 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 . 
