From Air to Trimix at depth

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Remy B.

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Have you experience a significant change in your state of mind and behavior by switching from air to trimix at 40m depth ?

The question is pointed out to nitrogen narcosis.

I guess it you are under the influence of CO2 it dosen't matter if you switch from air to trimix right ?

Yes I have less than 25 dives, does it offend you that I'm asking this, then more likely you will give an anal answer, and I'm not askign for those answers, my questions is directed to the divers that want to aport a positive in educated answer from which I can learn and make questions in a class room later or in another discussion with other more experienced divers.
 
When a buddy of mine took AOW, his instructor did an air share with each of the students onto some blend of trimix at depth on the deep dive, in order to demonstrate to the students the effects of narcosis.

He said it was pretty interesting for everything to become clear after breathing the trimix for a few minutes, but then also disturbing switching back to air with everything kind of fading back out.
 
Narcosis effects everyone differently. It even effects the same people differently on any given day based on conditions, hydration, stress, work load, to name a few. I prefer to dive mix only regardless of depth. Triox if you will. Trimix for deeper dives. So yes I noticed a differance.
Eric
 
Have you experience a significant change in your state of mind and behavior by switching from air to trimix at 40m depth ?

The question is pointed out to nitrogen narcosis.

I guess it you are under the influence of CO2 it dosen't matter if you switch from air to trimix right ?

Yes I have less than 25 dives, does it offend you that I'm asking this, then more likely you will give an anal answer, and I'm not askign for those answers, my questions is directed to the divers that want to aport a positive in educated answer from which I can learn and make questions in a class room later or in another discussion with other more experienced divers.

I don't think you quite understand the way Trimix works - you would not under most normal situations switch from air to trimix. Are you talking about recreational trimix?

You may have a travel gas like Eanx 28, you may have a travel Normoxic TRIMIX of 21/30 and a bottom gas of Tx 18/35 or in deep diving hypoxic 10/50. Then your deco gasses on the way up could be 50%, 80% and 100% ... Not usually Heliox filled... But generally there is no switch to or from air involved.

But in any case CO2 isn't what's narcing you - it's nitrogen. CO2 isn't supposed to be part of the equation.

There is a huge clarity difference between 120 feet on Eanx 28 and Air and even greater difference between Air and Trimix 21/30.

Hope that helps.
 
Can I tell I'm on 10/50 vs. air at 40m? Yes, but it's subtle rather than significant. At 220' it's not subtle, there's a definite wet blanket on my brain with air at 220' and I'm not having to think through that fog with 10/50 at the same depth. Still, I don't see the narcosis issue as a major problem at that depth on OC. On CCR, there's a different set of requirements and trimix makes a Hell of a lot more sense.

---------- Post added October 20th, 2014 at 10:39 PM ----------

There is a huge clarity difference between 120 feet on Eanx 28 and Air

Oh look, another "O2 is not narcotic/is less narcotic than N2" thread. This should be fun.
 
I don't think you quite understand

But in any case CO2 isn't what's narcing you - it's nitrogen. CO2 isn't supposed to be part of the equation.

There is a huge clarity difference between 120 feet on Eanx 28 and Air and even greater difference between Air and Trimix 21/30.

Hope that helps.

No I don't understand, any use of trimix, for what I have read the divers using trimix don't use air ( low % I think ), but my question was in case somebody had tried this or maybe as part of a tec class, just as to see the difference in state of mind or other.

The reason I mention CO2 is because the experts mention that the effects of CO2 mimic like the N2 narcotic effects.
 
The main advantage of trimix in the 30-40m range is ease of breathing. Because of the helium content, there is much lower gas density than air or weak nitrox. There are days when I've had to work to get down the shot line on a 35m dive and I had a banging headache from CO2. a bit of helium would have been nice.
 
....
The reason I mention CO2 is because the experts mention that the effects of CO2 mimic like the N2 narcotic effects.

CO2 does not cause narcosis. I don't know who the "experts" are you mention but they are not remotely expert. There is no significant amount of CO2 in compressed breathing gasses, it is an issue on rebreathers where the diver re-uses their exhaust gas. There is more Argon than CO2 in atmospheric air and that is very narcotic. Composition of Air

More on CO2 and diving here: CO2 Retention

I am unaware of any situation in which people are asked to switch from air to trimix for experience. Replacing Nitrogen with Helium will reduce nitrogen narcosis in proportion to the amount of helium/reduced nitrogen. Helium is not narcotic at SCUBA depths. Trimix starts to be a better choice of gas from about 35-40m. Narcosis with air is unpredictable and generally is agreed to start to become an issue at 40m+
 
At 40M you can switch from Air to Trimix (20/35) without any noticeable difference, but going from Trimix to Air at 40M you will notice.

On open circuit, all CO2 is exhaled, not an issue.
 
CO2 does not cause narcosis. I don't know who the "experts" are you mention but they are not remotely expert. There is no significant amount of CO2 in compressed breathing gasses, it is an issue on rebreathers where the diver re-uses their exhaust gas. There is more Argon than CO2 in atmospheric air and that is very narcotic. Composition of Air

More on CO2 and diving here: CO2 Retention

I am unaware of any situation in which people are asked to switch from air to trimix for experience. Replacing Nitrogen with Helium will reduce nitrogen narcosis in proportion to the amount of helium/reduced nitrogen. Helium is not narcotic at SCUBA depths. Trimix starts to be a better choice of gas from about 35-40m. Narcosis with air is unpredictable and generally is agreed to start to become an issue at 40m+


Actually CO2 is very narcotic! High levels will cause unconciousness. Nitrogen narcosis and CO2 retention have a syngergistic effect and will significantly increase the narcotic effect than either alone.

What people forget that as your depth increases so is your gas density. Increased gas densities cause increased work of breathing.Increased work of breathing will cause increased CO2 production.

Another reason why we dive Helium at increased depths is not only to avoid the narcotic effect of nitrogen, but to decrease gas density and with it, decrease work of breathing!

And yes, as many of you OC divers already know, you can get a CO2 hit when being on OC. It's a matter of producing more CO2 than you can breathe off.
 
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