In the final days of World War I, a US "Mystery Ship" embarks on a mission to locate and destroy a highly effective U-boat that has been targeting Allied vessels. Disguising itself as a harmless schooner, the ship is equipped with a powerful gun capable of sinking the enemy submarine. While refueling in the Canary Islands, the crew encounters locals with ties to the Germans and even Germans themselves, including the U-boat commander's sister, who is secretly waiting for the impending battle.
The Seas Beneath
A US Navy battleship disguises itself as a peaceful schooner and sets out to confront a powerful German U-boat in the Canary Islands, accompanied by a sneaky US submarine.
