Thunder Afloat

Wallace Beery

John Thorson

Chester Morris

'Rocky' Blake

Virginia Grey

Susan Thorson

Douglass Dumbrille

District Commander

Carl Esmond

U-Boat Captain

Clem Bevans

'Cap' Finch

John Qualen

Milo

Regis Toomey

Ives

Henry Victor

German U-Boat Officer

Addison Richards

Admiral Ross

Hans Joby

U-Boat Petty Officer

Henry Hunter

Ensign Dyer

Jonathan Hale

Admiral Girard

Leon Ames

Recruiting Officer (uncredited)

Arthur Belasco

Fisherman (uncredited)

Joseph E. Bernard

Fisherman (uncredited)

Wade Boteler

Recruiting Officer (uncredited)

Al Bridge

Fisherman (uncredited)

Rand Brooks

Listener (uncredited)

Don Castle

Radio Operator (uncredited)

Jack Chapin

Sailor (uncredited)

Tom Chatterton

Lieutenant (uncredited)

Jack Rube Clifford

Captain (uncredited)

Jules Cowles

Man with Finch (uncredited)

Leigh De Lacey

Mrs. Gill (uncredited)

Joe De Stefani

Fisherman (uncredited)

Edgar Dearing

Petty Officer (uncredited)

Richard Elmore

Lookout (uncredited)

Frank Faylen

Recruiting Officer (uncredited)

Budd Fine

Survivor (uncredited)

Allen Fox

Lookout (uncredited)

Frederick Lee

Sailor (uncredited)

Eddie Hart

Fisherman (uncredited)

Edward Hearn

Fisherman (uncredited)

Howard Hickman

Surgeon (uncredited)

Earle Hodgins

Fisherman (uncredited)

Clarke Jennings

Wireless Operator (uncredited)

Payne B. Johnson

Boy (uncredited)

Charles Jordan

Signalman (uncredited)

Lew Kelly

Sailor (uncredited)

Jack Kennedy

Fisherman (uncredited)

Milton Kibbee

Fisherman (uncredited)

Claire McDowell

Nurse (uncredited)

Larry McGrath

Radio Operator (uncredited)

Roger Moore

Orderly (uncredited)

Philip Morris

Fisherman (uncredited)

Forbes Murray

Naval Aide (uncredited)

Frank Orth

Old Sailor in Bilge Area (uncredited)

Syd Saylor

Wireless Operator Sending Coded Message (uncredited)

Harold Schlickenmayer

Engineer (uncredited)

Ferdinand Schumann-Heink

German Operator (uncredited)

Hans Schumm

German Sailor Looking for Wireless (uncredited)

Harry Semels

Cook on Tugboat (uncredited)

Lee Shumway

Sailor (uncredited)

Robert R. Stephenson

German Sailor (uncredited)

Harry Strang

Shore Patrol Sailor (uncredited)

Walter Thiele

Young German Sailor (uncredited)

Emmett Vogan

Junior Officer Standing by Map (uncredited)

Wolfram Von Bock

German Officer (uncredited)

Hans von Morhart

German Sailor (uncredited)

Doodles Weaver

Sailor (uncredited)