This is a tricky one!!!

[alonzo]

I've got another annoying question about fluids that really bugs me.
An underwater living chamber is wide open on the bottom for easy entrance. What keeps the water from rushing in? What’s the pressure inside? What would happen if it were punctured at the top? Describe what happens to the volume of gas inside as the thing is hauled up to the surface.

C if u can help me.
Alonzo

[arildno]

1.Water will "rush in" if the pressure in the gas is less than the water pressure at the entrance.
2. Gas will "rush out" if the pressure of the gas near an opening is greater than the pressure in the water by the same opening.

Use these results to solve your problem; BTW, welcome to PF.