On a large German diving exhibition in 1995 the Belgian company "Nautilus Overseas Corporation" showed an old idea in a new jacket: the Aquabul diving helmet.

It is made of cast iron with a Plexi glas dome. Above water the weight is about 20 kgs. Used in combination with an air compressor this is a very nice shallow water helmet for tourists to walk around reefs (or other things). It looks alot like the American Aqua Bell that was introduced in the 1970's.