Hans Hass

Hans Hass (23 January 1919 – 16 June 2013) was an Austrian biologist and diving pioneer. He was known for being among the first scientists to popularize coral reefs, stingrays and sharks. He was married to Lotte Hass.
He made documentaries filmed underwater. He led development of the aqualung and the making of the rebreather. He is known, too, for his energon theory and his commitment to protecting the environment.
Hass died in Vienna, Austria from natural causes. He was 94 years old. He is survived by his wife and daughter Meta.