Stranded in Hollywood by the German occupation of his country, Jean Gabin chose the novel "Moon Tide" [two words], by Willard Robertson, and handpicked his friend Fritz Lang to direct his American film debut. Ultimately, Fritz Lang left very early in production over friction he had with Gabin over Marlene Dietrich, with whom Gabin had an affair (ending in 1948) and with whom Lang was also involved. Archie Mayo then was hired.
Moontide's theme song, which Bobo and Anna first hear playing on the neighboring houseboat's phonograph, and which is later incorporated into the film's score, is "Remember" by Irving Berlin. Bobo thinks of Anna when the song is played in the Red Dot jukebox, and it is a breakthrough moment that changes his life.
The planned site at the San Pedro waterfront could not be used due to "war regulations" changed after Pearl Harbor attack. Some background process plates were shot at the harbor before entering World War II, and some were shot on location at Malibu, CA. Fox's designers also built a harbor and a curved rock jetty on a giant indoor stage set, further adding to the air of fantastic artifice.
The title theme is the exact same as for the 20th Century Fox adventure, O Segredo do Pântano (1941), which was directed by Jean Renoir whose movies made Jean Gabin famous, including the classic A Grande Ilusão (1937).
The surrealist painter Salvador Dalí was hired to conceptualize Bobo's drunken montage. He made three paintings and five sketches but reportedly deemed too bizarre, and the scene was shot with only some of his influence intact.