Departing Norfolk, Virginia 9 October 1943, "Cotten" arrived at Pearl Harbor 31 October. Here she joined the 5th Fleet, and on 10 November sortied for the invasion of the Gilbert Islands, screening the escort carriers providing air support and patrolling against submarines off Tarawa. Returning to Pearl Harbor 7 January 1944, she sailed with the vast Fast Carrier Task Force (then TF 58, later 3rd Fleet's TF 38) on 16 January for air strikes on the Marshalls on 29 and 30 January. Based at Majuro, "Cotten" participated in the Truk raid of 16 and 17 February; supported the landings at Emirau Island; and screened the carriers as they launched strikes on Palau, Yap, Ulithi and Woleai between 30 March and 1 April. Continuing her screening, she joined in covering the Hollandia operation from 21 to 24 April and air strikes on Truk, Satawan, and Ponape between 29 April and 1 May.