The first of director John Ford's three films for 1931 was the now-forgotten The Seas Beneath. Essentially a reworking of Ford's 1930 effort Men Without Women, the story concentrates on the WWI submarine crew captained by rough-and-tumble Bob Kingsley (George O'Brien). While trying to coerce a German sub into a winner-take-all battle, Kingsley learns that his sweetheart Anna-Maria Von Stuben (Marion Lessing) is an enemy spy, and that her brother and fiancee are officers on the German vessel. Adding to the intrigue is Mona Maris, a sexy Cabaret singer who likewise moonlights as a spy. The Seas Beneath was largely filmed on location in and around Catalina Island.