Frankenstein Island (1981)

From the director of "The Wild World of Batwoman" comes a movie about a group of balloonists who are stranded on an island where they are captured by Dr. Frankenstein's descendant, Sheila Frankenstein, who's been kidnapping shipwrecked sailors for years and turning them into zombies. When she learns that one of the captives is a doctor however, she tries to persuade him to aid her in her mad experiments.