Following "Roan", Lieutenant Fitzgerald reported to Naval Amphibious Base Coronado, California, where he attended counterinsurgency training. Upon completion he was assigned duties as the senior U.S. advisor at Coastal Defense Group Sixteen in Vietnam. This group's compound was located adjacent to the village of Co Luy, near the delta of the Tra Khuc River, and about 70 miles southeast of Da Nang. In this position, he advised the Republic of Vietnam Navy on defense measures and on the capture of military supplies and contraband destined for Viet Cong forces.