The new transport conducted shakedown and training exercises off California, departing for Pearl Harbor 4 December to join U.S. forces in the giant amphibious sweep across the Pacific. After her arrival at Pearl Harbor 10 December, "Hocking" embarked Marines and took part in amphibious exercises and rehearsal preparatory to the Iwo Jima invasion, destined to be one of the most important and hard-fought of the war. She joined the vast armada of transports 27 January 1945 en route to Eniwetok and after a stopover at that island base arrived Iwo Jima 19 February. There "Hocking" debarked her troops and unloaded equipment in the early waves of the assault. She then anchored offshore, received casualties, and departed 27 February for Saipan, where she arrived 2 March.