Movie was released on 1931-01-30, the IMDB rating is 5,9 (upd: 09-25-2020) and lasts 90 min. Directed by Jody Blose, John Ford.Overview
In the waning days of WWI, a U.S. ”Mystery Ship,” sets sail for the coast of Spain towing a submarine. Their mission is to find and sink a U-boat that has been especially effective in attacking Allied shipping. Posing as a harmless schooner, the mystery ship is in fact fitted with a formidable gun capable of sinking a U-boat. Stopping in the Canary Islands to refuel, the crew interacts with locals involved with Germans, and with Germans themselves, including the sister of the U-Boat commander, who is lurking offshore waiting for the coming battle.