[PSUBS-MAILIST] question about Diver Lockout.

["Jeremy Crawford" <ISMASC@hotmail.com>]

I have an air pressure question about diver lockout setups.

ok here is my understanding,

1. Diver goes from 1 ATM hull into lockout chamber.
2. lockout chamber is pressurized to ambient pressure.
3. hatch opens diver dives.
4. Diver returns closes hatch.

How does the pressure get dropped back to 1 ATM??  that is like creating a
vacuum at depth right? Perhaps I am mistaken somewhere in my understanding.
Any explanation would be appreciated.

Thanks!
Jeremy