Hans Hass

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.

Early years

Hass was born in Vienna; his father was an attorney and Hass initially pursued law. However, Hass had a formative encounter with the American diver Guy Gilpatric while on a Riviera holiday in 1938 which included underwater hunting and photography. After making expeditions to the Caribbean Sea and writing his first professional articles in 1938-39, in 1940 Hass switched from reading law to studying zoology and graduated with a Ph.D. from the University of Berlin in 1943 at the Faculty of Biology. His thesis was the first scientific research project that used an autonomous rebreather diving equipment. In his early diving he used rebreathers, which he had made for him by the German diving gear makers Dräger: he had these sets made with the breathing bag on his back, as he did not like the bag-on-chest "frogman look". Hass and his team of researchers logged over 2000 dives utilising oxygen rebreathers from 1942 to 1953.

Although Don Stewart, one of the first scuba operators on the Caribbean island of Bonaire, blames Hass for single-handedly hunting the Atlantic goliath grouper to local extinction in a book by Callum Roberts, the author clearly refutes that claim later in the same paragraph.