Lt. Cmdr. Richard 'Reef' Holloway
Cmdr. Dan Wendover
Dr. Carl Neilson Jr.
Sir Ian Hunt
Lt. David Milburn
CPO 'Grif' Griffin
Dr. Clifford Kent
Julie
Adm. Terhune
Justin Murdock
Helen Milburn
Frogman Carney
Frogman Powell (as Ken Becker)
Yeoman Chester Tuttle
Watkins
Narrator
Saucer Voice (voice)
Passerby (uncredited)