Upon arrival at Truk on 9 October, the two sisters were assigned to the Second Carrier Division to begin operations against American forces in the Guadalcanal area as part of the 3rd Fleet. On 15 October, the two carriers reached the vicinity of Malaita Island in the Solomon Islands and their aircraft discovered a resupply convoy for Guadalcanal that was escorted by the destroyer . Their aircraft attacked and sank the destroyer. The next day, they found the small seaplane tender, , in Lunga Roads offloading avgas into barges. Dive bombers from the sisters blew the ship's stern off, but failed to sink "McFarland". The two carriers were intended to play a prominent role in the Japanese effort to retake Guadalcanal Island and were assigned to the Advance Force for this operation. Their aircraft were supposed to provide air cover after the Japanese night attack that retook Henderson Field and then they were to be flown ashore, but "Hiyō"s machinery problems caused her to return to Truk. Some of her aircraft were transferred to her sister before she departed.