> So it starts out at as high a pressure as it will end up at the bottom? Ignoring shrinkage of the chamber (not insignificant), yes the human chamber will be

> So it starts out at as high a pressure as it will end up at the bottom? Ignoring shrinkage of the chamber (not insignificant), yes the human chamber will be at the same pressure at the surface and at the bottom. Counting in shrinkage due to pressure, the absolute pressure change will be less than the absolute pressure change you experience when you get on an airplane. > Because of course the problems of pressure are reversed in deep sea submersion as compared to high altitude flight. Of course the pressure problems are reversed. But both the airplane and the submarine prevent humans from experiencing decompression sickness by keeping the absolute change in pressure small enough that decompression sickness isn't an issue.