 They were assigned to the Southern Force on 8 January 1942 and departed four days later for the Dutch East Indies.The ships supported the invasion of the Palau Islands and the Battle of Ambon, attacking Allied positions on the island on 23 January with 54 aircraft.Four days later the carriers detached 18 Zeros and 9 D3As to operate from land bases in support of Japanese operations in the Battle of Borneo.