Based on

Movies like The Hot Pearl Snatch (1966)

A sailor runs into an old prospector in a bar in the Caribbean, who claims he has a map to a secret pearl bed off of an island populated by beautiful, lusty native girls. He gives up the map for a bottle of whiskey. The sailor isn't able to dive for the pearls because of a heart condition, so convinces a hooker to go along with him and be the diver, for half the proceeds. Complications ensue.