Paul Grogan

Bradford Dillman

Maggie McKeown

Heather Menzies

Dr. Robert Hoak

Kevin McCarthy

Jack

Keenan Wynn

Buck Gardner

Dick Miller

Dr. Mengers

Barbara Steele

Betsy

Belinda Balaski

Laura Dickinson

Melody Thomas Scott

Colonel Waxman

Bruce Gordon

Trooper

Barry Brown

Dumont

Paul Bartel

Suzie Grogan

Shannon Collins

Whitney

Shawn Nelson

Earl Lyon

Richard Deacon

Barbara Randolph

Janie Squire

David

Roger Richman

Jailer

Bill Smillie

TV Pitchman

Guich Koock

Boy in Canoe

Jack Pauleson

Father in Canoe

Eric Henshaw

Soldier

Robert Vinson

Girl

Virginia Dunnam

Water Skier

Hill Farnsworth

Water-skier

Diamond Farnsworth

Man in Boat

Bruce Paul Barbour

Man in Boat

Bruce Barbour

Screaming Woman

Robyn Ray

Dam Guard

Michael Sullivan

Dam Guard

Mike Sullivan

Brandy

Jack Cardwell

Tom, sentry guarding tent

John Sayles

Swimming Deb (uncredited)

Sally Bondi

Nick Palmisano

Dr. Robert Hoak (swimming double) (uncredited)

Eric Braeden

Bobby Sargent

Scuba Diver #2 (uncredited)

Joe Dante

Roger Creed

Hertz Clerk (uncredited)

Amy Holden Jones

Jailer

Bill Smille

Scuba Diver (uncredited)

Phil Tippett