The Golden Mistress.

Ann Dexter, daughter of an itinerant Haiti waterfront character, Carl Dexter, brings a golden idol, which her father her stolen at a voodoo ceremony, to Bill Buchanan, who is known along the waterfront as a man eternally on a treasure hunt. He agrees to let Ann accompany him in search of the treasure after a native he befriended gives him directions and certain voodoo secret charms. They follow an underwater passage to an island where they find a Pagan tribe. They learn that the golden idol is a burial symbol representing the dead and that hundreds of idols are at the bottom of the sacred burial lake.