Considering Nitrox Certification

[scubadude79]

I have NITROX, and it is great when you can use it.
Make sure that you have an LDS that will be able to fill NITROX, or you will not get to use it much.
It really helps to own your own tank that is dedicated for NITROX since it seems a little harder to find an LDS in the middle of the country that rents these tanks.

As far as the fatigue goes, I think it is different for each person. I think it slightly improves, my dad doesn't feel it at all, and others swear it does.

Best of luck!

 

[muddiver]

Nitrox does not prevent narcosis, you have not removed the narcotic - Nitrogen. It is just diluted down. To really affect the narcosis malidy you have to go to a mix that has no, or very little of any of the narcotic gases like HeliOx or a trimix with a small Nitrogen % to stave off HPNS. Most of the noble gases like Nitrogen are narcotic at higher pressures and will cause some narcosis when present.

 

[Kern]

Nitrox does not prevent narcosis, you have not removed the narcotic - Nitrogen. It is just diluted down. To really affect the narcosis malidy you have to go to a mix that has no, or very little of any of the narcotic gases like HeliOx or a trimix with a small Nitrogen % to stave off HPNS. Most of the noble gases like Nitrogen are narcotic at higher pressures and will cause some narcosis when present.

Nitrogen isn't a noble gas. It's not chemically inert. It is narcotic.

Helium is a noble gas. It is chemically inert. It is not narcotic.

 

[Interceptor121]

I would recommend you take the EAN course because that can be very useful when you can't afford long surface interval, for example because you have strong surf and are on a rubber boat or you want to squeeze as many dives as possible in one day. It is a good option to have in case you change your plan at short notice for example.

For what concerns the benefits of EAN mixes they are relate to extended no decompression limits.

There is no impact on narcosis because the effect of oxygen toxicity will generally kick in before that and besides oxygen has narcotic effects as well.

For what concerns fatigue there is a very good article on Undersea Hyperbaric Medicine. 2003 Winter;30(4):285-91. The test data in my opinion is significant enough and based on this articles there is no improvement on fatigue if you dive Air or EAN mixes

The article can be downloaded from here h**p://archive.rubicon-foundation.org/3975

 

[Rick Murchison]

Nitrogen isn't a noble gas. It's not chemically inert. It is narcotic.

Helium is a noble gas. It is chemically inert. It is not narcotic.

Oh, Lordie... let's get this stuff straight now, before it gets really confusing.
"Noble" gasses are those with "full" electron "layers" and are therefore chemically inert. This has nothing to do with narcosis, however.
Nitrogen (N₂), though not a noble gas and not chemically inert, is "physiologically inert" in that it isn't changed chemically by human body processes. It is dissolved and released as N₂ and doesn't change while it's in the body.
Compressed gas narcosis, commonly called "nitrogen" narcosis, is a property of all gasses; some are just more narcotic than others. The Narcotic properties of a gas appear to be fairly closely correlated with the gas's solubility in lipids (fats & oils). Helium, for example, is practically insoluble in lipids and has very little narcotic effect, while Argon - another noble gas - is very soluble in lipids and is very narcotic. Nitrogen is in between. Just exactly why gasses that are "inert" cause narcosis isn't well understood, but it appears they somehow change the conductivity - and therefore the ability to transmit impulses - in nerves (or in the myelin sheath) - by physical (as opposed to chemical) interference.
Looking at Oxygen, it's about twice as soluble in lipids as nitrogen, so one might infer that Oxygen should therefore be about twice as narcotic as Nitrogen and that Nitrox should be a bit more narcotic than air... but... since oxygen is not inert, and is both metabolized in the body and scavenged by hemoglobin, nerve tissue titers (concentrations) are typically about a sixth what would be expected if oxygen were inert like Nitrogen. So, perhaps we should expect about a third the narcotic effect from oxygen as we do from nitrogen, and Nitrox should be slightly less narcotic than air
Personally, I like the wording in SSI's Nitrox materials: "It is best not to assume any reduction in narcosis" when moving to Nitrox from air.
Rick

 

[boulderjohn]

Nitrogen isn't a noble gas. It's not chemically inert. It is narcotic.

Helium is a noble gas. It is chemically inert. It is not narcotic.

It is not that absolute. All gases have some narcotic effect. Helium's effect is much less than nitrogen's. Oxygen's is supposedly similar to nitrogen's.

Neon is less narcotic than helium, and it really would be the mix gas of choice were it no so expensive.

Hydrogen (not a noble gas) is better than neon, and it would be really great in a mix were it not for its tendency to have an unhappy relationship with oxygen. It can be used (and has been used) in mixes with the oxygen less than 4%.

However, all of this, including why they have this effect, is not well understood and open for debate. That is why it is possible for Europe to have a different belief than America. (I had never heard that before--this thread is the only place I have heard it.) It would not be right for those who have been taught that nitrox is less narcotic than air to blithely dismiss the arguments to the contrary. What we were taught is really still at the hypothesis stage, and it is possible that it is wrong.

For more details, see Mark Powell's Deco for Divers, pages 171-176.

 

[aubie85]

You do have DAN insurance right?

Yes I have DAN insurance. I am a relatively healthy person, and its funny how much better you take care of yourself when you don't have health insurance. However, that is not to say that since I have DAN insurance that I am a careless diver. Diving is pretty much the riskiest thing I do, and I am grateful that a service such as DAN is available

 

[Rick Murchison]

... Diving is pretty much the riskiest thing I do,...

Let there be no doubt, my dear... unless you're into jumping out of perfectly good airplanes or climbing mountains above 18,000', it is driving, not diving, that is the riskiest thing you do
Rick

 

[boulderjohn]

Let there be no doubt, my dear... unless you're into jumping out of perfectly good airplanes or climbing mountains above 18,000', it is driving, not diving, that is the riskiest thing you do
Rick

Walking through downtown Hobart may be riskier.

 

[Steve SDI/TDI HQ]

I am thinking about getting a nitrox certification. I heard that nitrox is much more 'refreshing' regular air, leaving the diver less 'fatigued' after diving. I was wondering if it is worth the extra effort(and money). Also, what gear (aside from the computer) will I have to 'upgrade' if I get nitrox certified?

Don't forget to register for your FREE nitrox tank wraps...

Here's the thread...http://www.scubaboard.com/forums/sdi-tdi-erdi/283762-get-your-free-nitrox-tanks-wraps-tdi.html