Hans Hass, Austrian biologist and diver (b. 1919)
Hans Hass (23 January 1919 – 16 June 2013) was an Austrian biologist and underwater diving pioneer. He was known mainly for being among the first scientists to popularise coral reefs, stingrays, octopuses and sharks. He pioneered the making of documentaries filmed underwater and led the development of a type of rebreather. He is also known for his energon theory and his commitment to protecting the environment.