Diving pioneer Commandant Yves Le Prieur patented a full face mask for snorkelling at the surface and shooting fish below with his rollerspear. Le Prieur was also involved with air supplied deep diving using commercial equipment of his devising, but this mask is not designed for submerging and the multiple snorkels have no water shut-off valves, although there are flow directing valves inside the mask. So even back then attention was paid to having large snorkel bores, something that modern designers seem to have forgotten. Few would want to dive with this monster on your head, but one has to remember when this was designed there was nothing else except modified firefighters' anti-smoke goggles and Alexandre Kramarenko’s patented mono-goggle.