It is not a theory. If you are not inside of a vessel which keeps the water pressure at normal atmospheric the only way you can breath is to use compressed air. That is how a scuba regulator works. It releases air at a pressure high enough for your chest to over come the pressure of the water column. On the surface there is actually 14.7psi of air pressure at sea level and for ever 33ft of depth in the water it increases 1 atmosphere. So at 33ft you need 29.4 psi to breath normally and at 66ft you need 44.1 psi, at 99' you need 58.8. If you did not exhale while accenting you would blow your lungs out. Ever yarded a fish up from depths??
If you were a mere 5' below the surface and had a mouth piece on a 2" hose running to the surface you would you would not be able to expand your chest to take a breath from it and would suffocate. Snorkels won't even work below about 2' of depth.
Take a 100 gallon tank with an open bottom and push it to 66' of depth and there would be a air bubble in the top of it and it you were inside you could breath from that bubble because it would be compressed by the water pressure to the 44psi. But, even a thin tank with an opening on the bottom would not collapse because the air pressure on the inside would equalize with the water pressure on the outside.
I sold my scuba gear when I was about 35.
At the 13,000 ft depth of the Titanic wreck the pressure is about 5,785psi and if you had a 22'x5' tube of air that would be about 432cu ft at the surface and if the bottom of the hull got a very small leak it would turn into a bubble about 14" in diameter in very short order. Even a pin hole could cut you like a knife. A car wash wand only runs about 2000psi
If you were a mere 5' below the surface and had a mouth piece on a 2" hose running to the surface you would you would not be able to expand your chest to take a breath from it and would suffocate. Snorkels won't even work below about 2' of depth.
Take a 100 gallon tank with an open bottom and push it to 66' of depth and there would be a air bubble in the top of it and it you were inside you could breath from that bubble because it would be compressed by the water pressure to the 44psi. But, even a thin tank with an opening on the bottom would not collapse because the air pressure on the inside would equalize with the water pressure on the outside.
I sold my scuba gear when I was about 35.
At the 13,000 ft depth of the Titanic wreck the pressure is about 5,785psi and if you had a 22'x5' tube of air that would be about 432cu ft at the surface and if the bottom of the hull got a very small leak it would turn into a bubble about 14" in diameter in very short order. Even a pin hole could cut you like a knife. A car wash wand only runs about 2000psi
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