"McDermut", detached from her second duty with TG 52.17, 4 August, sailed to Guadalcanal for rehearsal landings in preparation for the Palau offensive. By 15 September she was in position off Peleliu to support the 1st Marine Division as it landed, shifting to Angaur on the 17th to assist Army assault units. Departing the Palaus on 21 August, she headed northeast for ASW/AAW patrol duty during the occupation of Ulithi Atoll.