- Country: USA
- Genres: Drama, Romance, War
- Release: 1939-09-15
- Director: George B. Seitz
- Writers: Wells Root , Harvey S. Haislip , Ralph Wheelwright
- Language: English | German
- Stars: Wallace Beery (1885–1949) , Chester Morris , Virginia Grey , Douglass Dumbrille , Carl Esmond , Clem Bevans , John Qualen , Regis Toomey , Henry Victor , Addison Richards
- Runtime: 95 min
- Awards: N/A
- AKA: Thunder Afloat , Merien ukkonen (Finland) , Tonnerre sur l'Atlantique (France, French Republic) , Capitão Thorson (Brazil) , Viharos vizeken (Hungary) , Thunder Afloat (United States of America) , La tigre del mare (Italy) , 大西洋撃滅隊 (Japan) , Kolasis ypo ton Atlantikon (Greece) , Tonnerre sur l'Atlantique (Canada) , O Inimigo Invisível (Portugal, Portuguese Republic) , SOS U-båt! (Sweden)
- Plot: In a New England port town, Pop Thorson and Rocky Blake are rival tugboat owners. Thorson's boat has sunk in the shallow water while docked, and he is certain Blake sabotaged it for winning a lucrative contract of military supplies.
- IMDB:tt0032034
Thunder Afloat Cast · · · ALL
George B. Seitz
Director
Wallace Beery
(1885–1949)
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)