Benjamin Frankel composed a rejected score.
Leslie Norman started as director but was replaced.
In the first interior boat scene, the Doctor is reading "Uncharted Seas" by Dennis Wheatley, the book on which the film is based.
Last cinema feature of Jimmy Hanley.
Michael Carreras took over from the original director Leslie Norman. When Michael went over budget and schedule, his father James and the studio's solicitors arrived on set to shut the production down.
Michael Carreras' screen play was credited to his gardener, Michael Nash.
Original author Dennis Wheatly reportedly couldn't even remember his original 1938 novel on which the film was based.
The film's trailer incorrectly applies Tony Beckley's name to a shot of a man sword-fighting. In reality, the man shown is Charles Houston as Braemer, a crew member; Beckley plays Harry Tyler, a different character entirely.