Shark!

An American gunrunner, Caine (Burt Reynolds), arrives in a dusty town in Sudan after escaping corrupt government soldiers. Broke and desperate, he agrees to sign up as a deck hand to ichthyologist Dan Mallare (Barry Sullivan) and his mistress Anna (Silvia Pinal) who are supposedly collecting rare fish specimens. Caine soon discovers that his new employers are crooked treasure hunters look for gold bullion buried in the deep, shark-infested waters and that they would stop at nothing to get their hands on sunken treasure. (Signal One Entertainment)