Shock waves (1977)

The tourists Rose, Chuck, Norman and his wife Beverly hire the boat of Captain Ben Morris and his crew, the pilot Keith and the cook Dobbs. While navigating during the night, Keith crashes on a ship and on the next morning they realize that the vessel is stranded and Ben is missing. They go to a nearby island on a small boat and they find Ben drowned. They find a derelict hotel and soon they find they are not alone. A weird man asks them to go away since they are in danger. Later he explains that he was a SS Commander responsible for his powerful troop of zombie Nazis. Now they are returning and soon the group will die.