ALEXIS ROSENFELD / SCIENCE PHOTO LIBRARY ALEXIS ROSENFELD / SCIENCE PHOTO LIBRARY
Hydrogen gas cylinders containing hydrogen gas for special breathing mixtures for diving. Hydrogen is (like helium) an inert gas, and is used, instead of the nitrogen in air, to help counteract the effects of diving at the great pressures found at large depths. These pressures force lots of gas into body tissues and can poison the diver and upset body physiology, such as during nitrogen narcosis. Hydrogen and helium avoid some of these effects but cause other effects. Record depths of over 700 metres have been attained using a variety of hydrogen and helium methods. Photographed in Marseilles, France.
Model release not required. Property release not required.