Lt. Cmdr. John 'Twill' Twillinger

Gail MacKenzie

Dr. Jess Rogers

Jody Simms

Dr. Tad Johns

Lt. Robert 'Clem' Clemens

Sheriff Josh Peters

Sandy MacKenzie

Connie Blake

Seaman Fred Johnson

Sally

George Blake (lab assistant)

Mrs. Simms

Lewis Clark Dobbs

Seaman Wyatt (Radioman)

Seaman Morty Beatty

Monster Victim

Deputy Larry

Admiral Greenhouse

Deputy Scotty

Other Lock Watchman

Boy with Morty's Cap

Coroner Nate Brown

Gatekeeper

Patterson

Watchman at Lock 57

Seaman Howard Sanders

Davis - Resort Owner

Captain Masters

Deputy Brewer

Clarke

Writing

Directing

Sound

Directing

Sound

Sound

Production

Writing

Production

Crew

Camera

Art

Production

Editing

Sound

Art

Crew

Costume & Make-Up

Art

Costume & Make-Up

Crew

Crew

Camera

Costume & Make-Up

Sound

Sound

Directing

Crew

Sound