 Documentary survey of the activities of the United States Navy leading up to and during the first years of the American war in Vietnam. Footage of American warships during the controversial Gulf of Tonkin incident, which triggered American military action in Vietnam, is shown, as well as depictions of the landing of U.S. Marines on the beaches at Da Nang and Chu Lai. Naval advisors training South Vietnamese military personnel and Seabee construction units building military facilities and hospitals are also seen.