1943 and joined the V Amphibious Corps to prepare for Operation Flintlock, the invasion of the Marshall Islands. She sortied on 22 January 1944 with TF 52. On the 30th she and were detached to make a dawn strike on Carter and Cecil Islands of Kwajalein Atoll. All boats and troops were launched shortly before sunrise on 31 January 1944, and by 09:00 reported that they had killed 13 of the enemy on the island at a cost of one American killed and one wounded. The two high-speed transports were ordered to land 7th Cavalry Regiment reconnaissance troops on Bennett Islands before dawn on 5 February, and Manley was designated fire support ship. The area was well-covered, and the operation went off on schedule. Three days later Manley got underway as part of a transport screen for Hawaii, arriving Pearl Harbor on the 15th to train Army troops for future landings. On 30 May Manley joined Task Group 52.15 (TG 52.15) and departed for the invasion of Saipan. The high-speed transports arrived off Saipan on the night of 14 June and landed their marines on established beaches south of Garapan on 16 June. Thereafter, except for a trip to Eniwetok for supplies and night harassing fire on Tinian Town and airports on the nights of 9, 12, and 18 July Manley operated in the transport screen until 22 July. She returned to Eniwetok on the 22nd and, after a trip to Kwajalein, sailed to Pearl Harbor, arriving on 9 August, she began preparations for the next operation. On 10 September Manley took on board 50 tons of explosives, slated as reserves for underwater demolition team work in the proposed invasion of Yap. She left Pearl Harbor on the 15th and proceeded via Eniwetok to Manus, Admiralty Islands. There word arrived that the operation against Yap had been canceled and that the forces assembled would strike Leyte in the Philippines. Manley was then assigned to the bombardment and fire support group which arrived in Leyte Gulf early on 18 October. After entering Leyte Gulf, Manley was assigned screening stations off the southern transport area at Dulag. On the 19th she picked up casualties from , and transferred them to . After marking a navigational buoy during the early morning hours of the 20th, she headed toward Hollandia with TransDiv 28, on the evening of 21 October. En route, part of the