Diamond Connection (1982)
Crashed and sunken in a murky sea, a passenger plane had a very special package... a briefcase full of diamonds. These illegally acquired and transported missing diamonds become an irresistible challenge to a few interest groups. They will kill, deceive, and plot to capture the diamonds for themselves.
Well known actors, a good director, and apparently a decent budget. Check out this Swiss flavored cheezy film!
Director: Sergio Bergonzelli