Bad choice of names and somewhat misleading until you read the synopsis which doesn't make sense. I didn't know Russia had divers in 1798? The first diving suits with helmets weren't created till 1837 and scuba gear more than 100 years later. The first scuba dive was in 1942 and not sold until 1943. Maybe they are referring to diving bells but I doubt it. Maybe Capt. Nemo was real and a lot older than was told, or Jacque Cousteau time traveled to 1798?