After intensive shakedown along the California coast "Gunston Hall" prepared to sail for the Western Pacific, where she was to participate in every major operation from February 1944 to the end of the war, 18 months later. Loading 225 men from the 4th Marine Tank Battalion and 2 amphibious units, as well as 15 LVTs, 15 tanks, 17 LCMs, and 15,000 gallons of gasoline, "Gunston Hall" departed San Diego on 13 January 1944. On D-Day for the assault on Kwajalein, 1 February 1944, she stood offshore to unload her cargo as the Marines stormed the beaches on Roi and Namur Islands. "Gunston Hall" remained in the area to repair small craft until 6 February, when she reembarked her former passengers and equipment and sailed to Guadalcanal via Funa Futi. The pattern she set here held for her participation in eight further key invasion efforts in the Pacific as the Navy "Island-hopped" Marines and Army troops ever closer to the Japanese home islands.