Posted by TDI_2 on August 08, 2002 at 09:10:06:
In Reply to: Re: Oxygen? posted by tecdiver on August 07, 2002 at 19:54:10:
I agree with Chuck and with TechDiver both.
Pure O2 is a tech gas. The DanO2 card & training do NOT authorize you to use a DanO2 kit for offgassing yourself on the surface.
DanO2 oxygen is "for the brief interval of time during a rescue or assist between the time you have summoned EMR and before they arrive."
If you want to use pure O2 as a deco gas or surface interval gas, you should get Advanced Nitrox training. NAUI & TDI both offer this class as a part of their tech program. This would be the proper certification level for "using oxygen during your surface interval."
Pure O2 has certain limitations that you need to monitor, like pulmonary toxicity, CNS toxicity, O2 cleaning of all gear, delivery by scuba regulator or surface demand regulator.
Pure O2 is also expensive, which is probably why no one uses it as a surface interval gas.
The whole idea of tech gasses is to be able to get back to the surface, and then use the air and the atmosphere on the surface, during a sufficent surface interval, to offgas preparatory to a subsequent repetitive dive.
In tech diving, repetitive dives are still on the edge of what has been explored, and some agencies (like TDI) actively discourage technical repetitive diving as "too dangerous."
If you are not tech diving, you probably dont need oxygen during your surface interval.
And even if you are tech diving, and you do need oxygen during your surface interval, then you probably didnt learn anything at all during your tech diving training. NOBODY pushes the limit of DCS that close in recreational sport diving.