American Ninja 3: Blood Hunt [DVD] [1989]

This, the third issue in the American Ninja series, stars karate expert David Bradley who goes to Japan for ninja training so he'll be able to avenge his father's murder. Once trained, he enters in an international karate contest held by some no-goods who'd like to get their hands on the world's toughest fella so they can try out a new artificial disease they've created. (They figure the best way to test the disease is upon the toughest guy they can find.) Most action occurs on a Caribbean island.~Phillip Erlewine