Cutthroats (1984)

You're a backwater island's top diver and foremost expert on local shipwrecks. Which makes you perfect for the job a band of the island's shadiest characters has in mind for you. It's a simple business proposition: all you have to do is locate and salvage a fortune in sunken treasure. You stand to gain millions. The only drawback is, it could cost you your neck. Because to successfully recover the…