A young woman returns to her home in Africa after ten years. On the drive there, her chauffeur runs down a guy in the road. She's upset but he tells her that he wasn't human. This is confirmed by her grandmother, who insists there are zombies prowling the area. At this time a group of ship salvagers show up and they are interested in recovering a chest full of diamonds from sunken ship that's in the lagoon. But they are attacked by the zombies and one of the crew gets a broken neck that first night.
The old woman tells the story of how the diamonds have a curse on them, which caused the ship to sink in the first place. Ten men died--but have since been zombies. In fact, they look exactly the same except for their dead eyes. There are some interesting scenes of them fighting the salvagers underwater, which reminded me of that old "Diver Dan" show I watched when I was a kid.
This is an interesting zombie flick since it has "Pre-Romero Zombies" that aren't interested in eating the living. They are basically ghosts that still have control of their bodies.