PPNi and PSI

[ScubaPilot]

Still very new to diving. Loving, but I still have a thousand questions.

One that I've been thinking about lately. My Fiancee and I dive at the same time, same depth, same tanks (air), but I hit 500 and she's left with 1500-1800psi. (not in actuality, but for the question)

If we were to dive according to the tables, shouldn't she get some sort of credit since she didn't breathe as much compressed air, and/or shouldn't I be penalized more? It seems like the SRC calculation should be in the tables somewhere.

If a free diver can go down to (what's the record) say 500ft and come straight up without getting bent, then why doesn't less air consumption give you some sort of credit?

Sorry in advance if a stupid question, or if answered here before. I did a search but couldn't find anything.

 

[jonnythan]

No. It doesn't matter how much you breathe, since the majority of the N2 is exhaled. The only things that matter are the partial pressure of nitrogen and the amount of time you were exposed to it. The vast majority of the nitrogen you inhale is exhaled. A very tiny fraction of it is absorbed, some O2 is absorbed, and some CO2 is added to what you exhale.

 

[Charlie99]

http://www.scubaboard.com/showthread.php?t=30800

http://www.scubaboard.com/showthread.php?t=30240

These two threads discuss the question extensively.

 

[ScubaPilot]

Man - I really have to get better at searching this site.

Thanks guys, for the info and for the threads.