Men who are able to work and live underwater or in unbreathable Air.
Men with great physical strength, with healthy organs. There is no second
profession, with so great requirements of physical capability, like the
profession of a diver - not only occasional. To carry the nearly 200 pounds
heavy equipment outside the water, or to move this mass while walking underwater,
the breathing while fast changing pressure and, last not least, working
with all strength within a not at all safety air supply, require athletic
muscles, healthy lungs, strong heart and faultless function of all organs.