O2 Narcotic

[VTWarrenG]

O-ring,

Cool man. I'd like to hear what JJ has to say in person. GUE's official stance is certainly that trimix is required for all dives below 100' -- but I don't know how they feel about the bazillions of recreational divers doing recreational dives to 130' on air (or nitrox).

I have the feeling he's just going to say "given the choice, you should use trimix below 100 fsw."

- Warren

 

[O-ring]

I have the feeling he's just going to say "given the choice, you should use trimix below 100 fsw."

Then I will say, "ok, when can I sign up for Tech 1?" To which he will say, "hahahahahahahahhahhhhhhahahahahahahahhahahahaha bwahahahahahhahaahha," and I will crawl off into a corner and keep diving EANx30 to 115 fsw until I am worthy to wax his car.

 

[The Iceni]

Hi O Ring,

I completely agree with you, and was not arguing that a dive to 115 ft with nitrox 30 was not OK.

In UK units this is 35 metres with an END of 30 M (97 ft).

This is what prompted my post;

On one of my last wreck dives I went to 43 m (140 ft) on Nitrox 26, with an END of 39.5 M (128 ft) and was pretty narked on the sea bed. On ascending to the deck of the wreck at 35 M (114 ft) with an END of 32 M (104 ft) I was absolutely fine for the rest of the dive.

I do believe that an END of 40 M (105 ft) is my current narcosis-free limit so aim to train to use Trimix and use it for any dive deeper than 38 M and also aim to keep the END to below that figure.

Warren, if oxygen is as narcotic as nitrogen the Trimix END calculations mean nothing, but I gather they work. However, I have no grouse with increasing safety and erring on the side of caution!


Kind regards,

 

[O-ring]

I think we all agree then. My basic thoughts are that since o2 is metabolized and inert gasses are not (n2, he, etc.) that figuring END using o2 should at best be modified to account for the metabolizing of some of the gas for body processes. In lieu of my lack of knowledge in that area, I am doing as you mention and just leaving o2 out of my END calculations for these dives. If I go on my basic premise that o2 is *probably* (only my opinion/experience with nitrox) not quite as narcotic as n2, 30% will be much safer than doing these dives on air.

I accept the fact that trimix would be ideal for these dives, but not all of us have the skills, expertise, and access (not to mention certification) to he.