Benefit of Nitrox?

[NateS]

So, scientific evidence aside, it still "seems reasonable" to you?

I don't see scientific evidence about subjectively "feeling better". The studies focus only on measuring "fatigue", which is only one of many DCS symptoms. IMHO, it is entirely reasonable that nitrox reduces DCS symptoms. Until that is actually studied I don't think it is time to pull the "but science!" card.

Don't confuse the "rate" at which an event is observed to occur with the concept that the occurrence of that event is due to "chance."

Dive conservatively and the likelihood that you will experience DCS during your lifetime is virtually zero. On the other hand, there's all kinds of things you can do to increase that likelihood to darn near 100% on any given dive. In neither case is the potential for getting hit due to chance.

Good point. I still wonder what the 0.01% rate means, since there is such a wide range of DCS effects.

Nate,

Please stick to a topic for which you have some knowledge, experience, and expertise.

Good diving, Craig

Hi Craig! Welcome to the Basic Scuba Discussions forum! This is a public forum intended to be a very friendly, "flame free zone" where divers of any skill level may ask questions about basic scuba topics without fear of being accosted. If you would like to discuss something I have stated incorrectly, that would be helpful. If you don't actually have anything useful to contribute, then just keep on trolling.

 

[RJP]

Good point. I still wonder what the 0.01% rate means, since there is such a wide range of DCS effects.

Given that...

• No one knows how many people actually dive
• No one knows how many dives those people actually do
• No one knows the profiles of those dives
• No one knows how many of those dives have zero DCS effects
• No one knows how many of those dives have subclinical DCS effects
• No one knows how many of those dives have clinical DCS effects that are ignored or otherwise not presented to a medical professional
• There are some data about DCS effects/cases that are reported to the people who come up with statistics on this kind of stuff

I think it's safe to say that the 0.01% rate means "we don't really have the foggiest idea" ultimately.

 

[Searcaigh]

But here's another consideration: how much gas do you need to conduct a dive to 90ft max for 65min, gradually ascending as NDL closes in? Since you specified "vacation diving" I'll assume you're diving an AL80. Quick V-planner run suggests that descending to 90ft and then chasing NDL for 65 minutes on either 36% or 32% - including a 3min safety stop - requires 104cf of gas.

Depends on your SAC rate

 

[Nasser]

I'm currently reading the recently published Deep Into Deco by Asser Salama. This is an excellent overview of decompression theory with some of the most recent theoretical models being discussed and used. There is an entire chapter devoted to Nitrox with some more recent findings on the benefits of its use. I would recommend that those interested in deco theory, use of Nitrox and Mixed gases check this book out.

I will write a small review once I'm done reading it and do a brief comparison with the excellent Deco for Divers by Mark Powell. Stay tuned...

 

[RJP]

Depends on your SAC rate

The reality is that - given typical recreational dive profiles, average gas consumption, and an AL80 - the benefit of diving nitrox for the average recreational diver is that it allows them to stay underwater long enough to drown... but not long enough to get bent.

:cool2:

 

[KenGordon]

I don't believe that Nitrox has any benefit regarding fatigue. The actual diving bit of a day diving is the least tiring I find. Last week we canned a dive at the point of jumping off the boat. I didn't feel any less tired for not having got wet.

Doing nitrox is the same as diving shallower wrt nitrogen absorption. You will end up will less nitrogen in solution at all points in the dive, even if you reach the NDL, just as if you had stayed shallower.

I try to use the best mix for any given dive.

It is quite frustrating to dive with someone on air and either end a good dive early or hang about for them to do stops simply because they didn't spend an extra £6 on gas.

 

[AfterDark]

I suppose nitrox benefits some divers because it is very popular. Unfortunately I am not one of those divers, something I wish I'd known before I wasted the money on the cert. If you run out of bottom time before you run out of gas then nitrox is for you. If however you are like me and need doubles to reach or exceed your NDL stick with air, at least here it is cheaper and there is no practical depth depth limits on it.

Some people claim that it makes them feel better post dive. I never felt any different, I'm just as tired after a dive with nitrox as I am with air. Because I was trained 45 years ago O2 PP, O2 exposure and toxicity was something we were taught in classes back then. Everything I paid to learn I already knew. Also I paid quite a bit to get 4 tanks O2 cleaned because the LDS here doesn't bank they only blend. I used them with nitrox about 6 times for the last 3 years they've seen nothing but 21%. I wished I'd bought a new piece of gear instead or getting nitrox certified. Nitrox was a gross waste of time and money for me.

 

[bryanmc57]

Hi Craig! Welcome to the Basic Scuba Discussions forum! This is a public forum intended to be a very friendly, "flame free zone" where divers of any skill level may ask questions about basic scuba topics without fear of being accosted. If you would like to discuss something I have stated incorrectly, that would be helpful. If you don't actually have anything useful to contribute, then just keep on trolling.

Just curious... How many nitrox dives do you have Nate?

 

[Aotus]

I suppose nitrox benefits some divers because it is very popular. Unfortunately I am not one of those divers, something I wish I'd known before I wasted the money on the cert. If you run out of bottom time before you run out of gas then nitrox is for you. If however you are like me and need doubles to reach or exceed your NDL stick with air, at least here it is cheaper and there is no practical depth depth limits on it.

Some people claim that it makes them feel better post dive. I never felt any different, I'm just as tired after a dive with nitrox as I am with air. Because I was trained 45 years ago O2 PP, O2 exposure and toxicity was something we were taught in classes back then. Everything I paid to learn I already knew. Also I paid quite a bit to get 4 tanks O2 cleaned because the LDS here doesn't bank they only blend. I used them with nitrox about 6 times for the last 3 years they've seen nothing but 21%. I wished I'd bought a new piece of gear instead or getting nitrox certified. Nitrox was a gross waste of time and money for me.

Nope. Even with a poor sac rate, the equivalent TIME you spent underwater on an equal dive comes with less accumulated nitrogen in your body, this means shorter surface intervals and less risk of DCS. It's not JUST about the (deceptively worded) plug by PADI about longer NDL time. I do agree, however, that the cost of the certification is stupid. They should include it in an OW cert for no extra charge in my opinion.

 

[AfterDark]

Thanks. Agree with you. Just don't know why the myths of lower air consumption and less fatigue continues to permeate. Placebo effect probably.

I don't know that this really happened but if I was selling nitrox I'd push the fatigue angle. Something so subjective is always going to have believers. Even with all the evidence to the contrary just look at the posts in this thread. The power of suggestion is very strong.