Hall gained mainstream attention for his role as Chief Phillips in Francis Ford Coppola's 1979 war classic "Apocalypse Now", in which his character leads the rest of crew upriver from Vietnam to Cambodia so that Captain Willard (Martin Sheen) can complete his mission to assassinate Colonel Kurtz (Marlon Brando). To prepare for the role, Hall did research to accurately portray someone experiencing the Vietnam War first hand. The actor described filming in the Philippines as "exotic" and added that "it was all fun."