Dempsey
Laura
Water Bailiff
Dr. Mercer
Adrian Foote
Gordon Shoals
Andy Maclean
Isabel
Wee Wullie
Dr. Abernathy
Guideon
Macleish
Tow Truck Driver
Dr. Hunter (as Deborah Weston)
Dr. Muller
Englishman
Norwegian
Repairman
First Fisherman
Second Fisherman
Tommy
Mary McFarlane
Rhoda Tait
Dr. Binns
Aged Professor
Scientist (uncredited)
Reporter (uncredited)
Cameo appearance (scientist) (uncredited)
Miss Woodhurst (uncredited)
Student Messenger (uncredited)
Fisherman (uncredited)