 On 30 November, Zuihō, together with the escort carriers Chūyō and Unyō, departed Truk for Japan, escorted by four destroyers. The Americans had cracked the Japanese naval codes and positioned several submarines along their route to Yokosuka. Skate unsuccessfully attacked Zuihō on 30 November, while Sailfish torpedoed and sank Chūyō five days later with heavy loss of life. From December to May 1944, Zuihō ferried aircraft and supplies to Truk and Guam although she was reassigned to the Third Carrier Division on 29 January, together with the converted carriers Chitose and Chiyoda. Each of the three carriers was intended to be equipped with 21 fighters and 9 torpedo bombers, but this plan was changed on 15 February to a consolidated air group, the 653rd, that controlled the aircraft of all three carriers. While fully equipped by May with 18 Zero fighters, 45 Zero fighter-bombers, 18 B5Ns, and 9 Nakajima B6N "Jill" torpedo bombers, the air group's pilots were largely drawn from the two most recent classes and lacked experience. The ship sailed for Tawi-Tawi on 11 May in the Philippines. The new base was closer to the oil wells in Borneo on which the Navy relied and also to the Palau and western Caroline Islands where the Japanese expected the next American attack. However, the location lacked an airfield on which to train the green pilots and American submarines were very active in the vicinity which restricted the ships to the anchorage.
