Movie Cast (30)

• 

  John Agar

  Prof. Clete Ferguson

• 

  Lori Nelson

  Helen Dobson

• 

  John Bromfield

  Joe Hayes

• 

  Nestor Paiva

  Captain Lucas

• 

  Grandon Rhodes

  Jackson Foster

• 

  Dave Willock

  Lou Gibson

• 

  Robert B. Williams

  George Johnson

• 

  Charles Cane

  Police Captain

• 

  Loretta Agar

  Woman on Boat (uncredited)

• 

  Bill Baldwin

  Patrol Boat Dispatcher (voice / uncredited)

• 

  Jere Beery

  Photographer (uncredited)

• 

  Ricou Browning

  The Gill Man (in water) / Lab Technician (uncredited)

• 

  Diane DeLaire

  Miss Abbott (uncredited)

• 

  Mike Doyle

  Cop (uncredited)

• 

  Clint Eastwood

  Jennings (uncredited)

• 

  Jack Gargan

  Skipper (uncredited)

• 

  Charles Gibb

  Cop (uncredited)

• 

  Brett Halsey

  Pete (uncredited)

• 

  Don C. Harvey

  Mac - Spotlight Party Leader (uncredited)

• 

  Tom Hennesy

  The Gill Man (on land) / Marineland Diver (uncredited)

• 

  Don House

  Diver (uncredited)

• 

  Robert F. Hoy

  Charlie (uncredited)

• 

  Ned Le Fevre

  Newscaster (uncredited)

• 

  Sydney Mason

  Police Announcer (uncredited)

• 

  Robert Nelson

  Dr. McCuller (uncredited)

• 

  Patricia Powers

  Girl in Convertible

• 

  Bert Stevens

  Search Party Member (uncredited)

• 

  Charles Victor

  Policeman (uncredited)

• 

  Robert Wehling

  Joe (uncredited)

• 

  James R. Wolfe

  Man at Tank (uncredited)

Movie Crew (32)