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TRACI
10-15-2007, 16:46
I am trying to decide if I want to get nitrox certified before my next trip to Cozumel in January. I usually try to get in atleast two dives per day, by the 5th day of diving our last trip I was a little bit tired, so I did not dive the 5th day, I do not dive very deep, 85' max, would diving with Nitrox cause less fatigue?

ScubaToys Larry
10-15-2007, 17:05
People argue that one back and forth. For sure you'd be reducing your N2 levels, and could get in more dives because of it - or add to the safety factor, but for fatigue only reasons - I'd probably say that while some folks say they feel less tired - there is not much scientific research or proof.

Divingguy
10-15-2007, 17:08
Not all shops in Coz carry Nitrox, and those who do certainly charge extra for it. I do like it and use it when it is available, because I usually try to get in 3 or 4 dives a day on a trip like that. Nitrox can allow for longer dive times and/or shorter surface intervals IF you are diving a computer set up for it. Cons are the additional cost, questions about being able to verify the percentage of mix you are getting, and the risk of oxtox if you go below your MOD.

No Misses
10-15-2007, 17:08
Nitrox vs fatigue: There seems to be a lot of contention about this. I personally believe that the lower level of nitrogen in my system makes me less tired at the end of the day. I do a livaboard trip every spring. We do 5-6 dives per day for 4 days. There is no way that we could do this on air. We need EANx to shorten the Surface Interval.
I recommend that you get the training. This will open up opportunities to dive more often and that's always a good thing ;-)

wgt
10-15-2007, 17:36
I am trying to decide if I want to get nitrox certified before my next trip to Cozumel in January. I usually try to get in atleast two dives per day, by the 5th day of diving our last trip I was a little bit tired, so I did not dive the 5th day, I do not dive very deep, 85' max, would diving with Nitrox cause less fatigue?

In response to your specific question concerning whether you would be less fatigued following several dives with nitrox versus several dives with compressed air, the answer is fairly straight forward. Science does not permit us to say with any degree of certainty that this would be the case. The relevant research is simply lacking. I am thus not saying that nitrox does not reduce the fatigue associated with recreational diving. I am only saying that available evidence does not clearly indicate fatigue-attenuating effects of nitrox in this context. In other words, we don't know.

What you can anticipate (see other similar threads) is that a great number of posters will react to your question with personal testimony. A number will say that they experience reduced fatigue. Others will report not noticing reductions in fatigue. As a rule, I tend not to place too much weight on testimonial evidence. Therefore, I would recommend that you balance the empirically established or at least theoretically justified advantages and disadvantages of nitrox for the type of diving that you plan to do.

Advantages of Nitrox:
1. It can be used to reduce risks of decompression sickness by observing compressed air-related No Decompression Limits.
2. It can increase bottom time (within limits) without increased risk of decompression sickness.
3. The bottle comes with a sporty yellow and green label.
4. It can be used to limit surface intervals.

Disadvantages of Nitrox
1. Maximal depths are reduced due to risks of toxic effects of high-pressure oxygen.
2. Time and money is required for nitrox certification.
3. Nitrox is often (but not always) vended more expensively than compressed air.

Personally, I prefer to dive nitrox:
1. When bottom times for a few dives are likely to be extended significantly. For me, this benefit is seen at depths approaching and exceeding 18m (60 ft).
2. When many dives are going to be done in succession (e.g., on a live-aboard) while computing No Decompression Limits for compressed air.

You, of course, may differently weight the advantages and disadvantages and opt for a different pattern of use. Even if you ultimately decide not to dive nitrox at all, however, I would still recommend that you get a nitrox certification, if only for its educational value.

tremtech
10-15-2007, 18:03
I agree with Wgt, plus the coarse will give you some more serious time on your dive tables, you will be a wiz at the end of the course .

comet24
10-15-2007, 18:09
Benefits are you can reduce you nitrogen loading and add more BT and dives per day. You are also adding a safety factor but reducing the nitrogen in you body. As for feeling less fatigued well that up for debate.

I going on a liveaboard at the end of this month and will be diving nitrox.

cummings66
10-15-2007, 21:43
To correct a prior posting about the benefit of Nitrox. It's primary purpose is to reduce the Nitrogen loading. How you use that is up to you, some extend bottom times with it. However, if you dive Nitrox and use it to extend the bottom times to it's limits like you would do with air then it is no safer than diving air. It's only safer if you dive Nitrox as you would air which means you're taking the reduced Nitrogen with no tradeoffs.

I personally have been diving Nitrox for only a couple years and I do not notice myself feeling better after numerous dives. What I noticed making that difference was coming up slower and doing an extra stop for a minute at half my max ATA. More benefits to that than diving Nitrox.

Chocoholic
10-15-2007, 23:05
I have been considering taking a nitrox class too. This is good info.

Scubastud16
10-15-2007, 23:48
Take it! Best money you can spend in diving classes, especially if you do several dives in a day. Can you say hellooooo short SI's?

kyfriedchipper
10-16-2007, 01:23
You can do this Nitrox course online too - check it out http://www.onlinenitroxlessons.com/nitroxlessons.html - $59.95 too...

cooltravelnews
10-16-2007, 01:43
Nitrox makes diving safer. It helps your muscles recover faster & yes you will feel better. I just spent a week on Bikini diving 175' two a day dives, and then blowing out with 70% oxygen. It flushes you out fast and allowed us to dive deep two a day.

I have dove Cozumel about a dozen times and the last half on nitrox. I definitely felt better.:smiley20: I felt better in Palau where the nitrox was FREE! Go nitrox. There are only a few sites where you could or would go deep.

You can do what I did on Truk use it on the last shallow dive. Cheaper and definitely safer if you are close to max depth.

Have a loud depth alarm set.

danielh03
10-16-2007, 02:10
You can do this Nitrox course online too - check it out http://www.onlinenitroxlessons.com/nitroxlessons.html - $59.95 too...


How does that work? Say if you have a PADI or ANDI C-card, how would you get your agency to send you one with Nitrox in it? Or do you just have two seperate cards?

Zenagirl
10-16-2007, 07:19
What blend of nitrox would you dive to 175'? Seems like tri-mix would be in order for a deep dive like that.

cummings66
10-16-2007, 09:42
You wouldn't use Nitrox for that, the MOD is such that you're diving air at those depths. To be honest I think what he did was too risky for my diving style, multiple dives to 175 fsw, breathing 70% and hoping to reduce the NDL without any means of knowing you did so. Why 70% and not 100%? The numbers for the best mix would be; Using a 1.4 PPO2 the mix for 175 fsw is 22%. Might as well use air because there's no way 1% is noticeable.

shadragon
10-16-2007, 10:22
NITROX is excellent for multiple dives over multiple days as it reduces your N2 exposure. O2 exposure is not usually a problem for recreational profiles, but if you have a good computer to track this then life is good. I read a few other comments about shortening SI's and the like. NITROX use should not encourage you to take shortcuts elsewhere.

As an example, I used NITROX in the Red Sea and did 5 dives in one day. I stayed 30' above the max depth of the mix. I had a minimum of 2 hours SI between each and stayed well hydrated and out of the sun in-between.

Take the course before you go then enjoy yourself when you are there...:smiley20:

No Misses
10-16-2007, 10:31
I believe that cooltravelnews was talking about doing air dives to 175 fsw and then scrubbing with EAN70 at, or before, the safety stop. I don't have the charts in front of me but I would guess that the MOD of EAN70 would be somewhere around 40 fsw. I am not a tech diver. So, the theory stuff is a little out of my league. Gasses move from higher consentrations to lower consentrations. By going to EAN70 at ~40 fsw you start offgassing sooner. I have seen this argument go back and forth. The current deco software shows that going to 100% O2 at 20 fsw actually gets you out of the water faster than if you do 70 or 80%. Yes, you do get to start earlier (deeper) with these mixes, but the 100% at 20 fsw scrubs out nitrogen faster (or so I have heard). If there are any tech divers out there that want to correct my assumptions, feel free to do so. Please put it into layman's terms if at all possible. Thank you.

cummings66
10-16-2007, 10:48
If he was doing technical dives I could understand, but in the context of the thread I assumed it was recreational usage.

I'd be interested in what the dives were and how he did them. I'm guessing a wreck of some sort?

Zenagirl
10-16-2007, 15:24
Supposedly he's talking about a trip he took to Bikini. Frankly, he's not a credible poster to me because he talked about using an Oceanic computer at Bikini and if you check their website, Oceanic computers are not allowed at Bikini. Heck, they even say not to bother to even bring it because it won't be allowed, period.

Boris42
10-16-2007, 16:35
Cshel and I finished our Nitrox class just last night. We decided to go ahead and get it because we've signed up for a weekend of wreck diving in two weeks. We'll be between 65' and 115' on 4 wrecks over two days. It just made sense to go ahead and get certified so we didn't have to be the first to hit our NDL's for the whole weekend.

As well, next spring we want to book a liveaboard for a week of repetitive diving in the range that Nitrox gives us the real benefits.

Lone Frogman
10-17-2007, 16:31
Nitrox makes diving safer. It helps your muscles recover faster & yes you will feel better. I just spent a week on Bikini diving 175' two a day dives, and then blowing out with 70% oxygen. It flushes you out fast and allowed us to dive deep two a day.



mmmm?

cummings66
10-17-2007, 16:59
Having read the dive site data there, it appears to me they do things their own way and believe that because they've been lucky to date it's the only way to do it.

They ban Oceanic computers, but not all of them because you'll see them warn you about the VR3. I wonder if a computer like the VT3 is ok with them because it can handle 3 gas mixes during a dive.

It seems to me that it's not the way I'd choose to dive those sites I guess, and they use 75% for what it's worth. Why 75% and not 100% at the depth they hang at I don't know unless it's easier to pump the tanks up that way.

So, he might have done the dives he says like he claims, but I think he might have been one of the insta wonder divers they produce out of Ow divers because he surely didn't use Nitrox on the dive. A nitrox diver wouldn't call it that.

Zenagirl
10-17-2007, 19:49
Having read the dive site data there, it appears to me they do things their own way and believe that because they've been lucky to date it's the only way to do it.

They ban Oceanic computers, but not all of them because you'll see them warn you about the VR3. I wonder if a computer like the VT3 is ok with them because it can handle 3 gas mixes during a dive.

It seems to me that it's not the way I'd choose to dive those sites I guess, and they use 75% for what it's worth. Why 75% and not 100% at the depth they hang at I don't know unless it's easier to pump the tanks up that way.

So, he might have done the dives he says like he claims, but I think he might have been one of the insta wonder divers they produce out of Ow divers because he surely didn't use Nitrox on the dive. A nitrox diver wouldn't call it that.

Except that in another thread he was claiming to have used an Oceanic DataMax Pro Plus 2, not the VR3..... I remain skeptical of his "claims".

cummings66
10-17-2007, 21:16
I'll tell you what, if I had the time and money this is a dive I would love to do, but it would be a proper dive with TriMix and deco procedures. Not some made up BS that because they've not bent anybody is good to go and withstood the test of time.

I could be wrong, but the website makes me think of them as "cowboys" and someday they're going to kill somebody.