What do veteran divers think about Air vs Nitrox

[tropicaledit]

Hey all, I'm new to the sport (apprx 20 dives). I'm wondering if how the verteran divers out there feel about Air vs Nitrox. I just saw a thread from a diver whos been
diving for MANY years, said he's never used Nitrox. My thought is, if divers, who are highly experienced aren't using it, why aren't they.

My understanding with Nitrox and O2 Toxicity is, theres basically no warning signs once you pass 1.6 ata, and your going to more than likely meet your maker. As opposed to getting Narced, hopefully you understand that your getting loopy and start to ascend. Aside from fatique, there seems to be more room for seeing another day
with air. Thoughts?

 

[markfm]

I'll be curious to see the answers...
PADI (and likely others) instructs to keep your Max Operating Depth (MOD) so that you're at no more than 1.4 ATA, with a Contingency Operating Depth (COD) of 1.6.

Diving EAN32, your MOD is 111 feet -- a reasonably deep dive -- and COD is at 132'. With EAN28 the numbers are 132' and 156', respectively -- in other words the EAN28 MOD is greater than the PADI limit for rec diving (130').

Why Nitrox? Increased bottom time for a given depth, as long as you stay within the MOD for the mix, since you're building up Nitrogen less rapidly. Alternately, less Nitrogen buildup than air for a given depth and time.

The US Navy Diving Manual is available online, has a chapter on Nitrox, if you want to read a bit about it.

(This is NOT a recommendation to follow the USN manual, their practices are specific to their application, which is not recreational diving.)

I don't claim to be a veteran diver, but the question is pretty straight-forward.

 

[Thalassamania]

Just remember the tee shirt, it showed two fried eggs and had the caption, "This is you brain ... on air!" You need to control your depth and time, and keep track of your oxygen clock in addtion to you nitrogen status, but that's it. Most "veteran" divers I know use as rich a mix as they can as often as they can.

 

[The Chairman]

I have been diving since 1969 and I use NitrOx whenever possible. I believe DAN recommends it for all divers over 40 and that includes me!

 

[The Chairman]

As for warning signs... they are there. Unfortunately, most people don't recognise them. Remember Ventid...

Visual
Ears/tinitus
Nausea
Tingling
Irritability
Disorientation

 

[MrConclusion]

I've always enjoyed diving Nitrox, but it's not always practical (as in, readily available) at many dive locations. In those cases, I'm happy with air.

Working as a divemaster, it's common to spend a weekend in relatively intensive quarry diving. Mornings with 'Open Water' students, afternoons with 'Advanced Open Water' or 'Rescue' classes, plus night dives and other specialties. With all that diving, plus lugging gear up and down the hill, I'm happy for anything that reduces my nitrogen loading and to get the most out of my sometimes paltry surface intervals!

On a dive boat where air is the only option, the dive operation will already adjust their dive schedule & surface intervals accordingly, so it's not a big deal. But if I were in a "dive as much as you care to dive" situation such as a liveaboard or unlimited shore dive package, I'd definitely pay extra for nitrox.

 

[MikeFerrara]

Hey all, I'm new to the sport (apprx 20 dives). I'm wondering if how the verteran divers out there feel about Air vs Nitrox. I just saw a thread from a diver whos been
diving for MANY years, said he's never used Nitrox. My thought is, if divers, who are highly experienced aren't using it, why aren't they.

There are certainly many very experienced divers who use nitrox. the fact that we may know of "one" who doesn't, certainly doesn't establish a trend.

Run the numbers for some dives or series of dives and it's pretty easy to see the advantage...less N2 loading for the same amount of bottom time.

My understanding with Nitrox and O2 Toxicity is, theres basically no warning signs once you pass 1.6 ata, and your going to more than likely meet your maker. As opposed to getting Narced, hopefully you understand that your getting loopy and start to ascend. Aside from fatique, there seems to be more room for seeing another day
with air. Thoughts?

I wouldn't consider using nitrox as more dangerous. As a practical matter, I don't use it for every dive or for every series of dives but when it's available and when it makes sense, I use it.

 

[Don Burke]

For wall diving, the oxtox concerns are a big deal. Around here, the wrecks are on a relatively flat bottom, so selecting an MOD that would require a backhoe to reach is pretty easy to pull off. That makes one concern go away for most of my dives.

I have been doing some beach diving lately, so using EAN for a thirty foot dive has not seemed like a good option.

At around fifty feet, the gains in bottom time get worthwhile for one or two dives a day. For a liveaboard where it is three to five dives a day for days at a time, a somewhat shallower depth is where the payoff starts.

Overall, I think EAN is a very good thing. In some applications, it adds much to the dive. In other applications, it is a waste of money. In yet other applications, it greatly increases the risk.

It adds one more thing to manage. I do not think it adds much of a burden as much of the tracking is done on a surface interval anyway.

 

[MikeFerrara]

As for warning signs... they are there. Unfortunately, most people don't recognise them. Remember Ventid...

Visual
Ears/tinitus
Nausea
Tingling
Irritability
Disorientation

The signs may or may not be there with convulsions sometimes being the first sign. I have been told by a couple of divers who have dived VERY high PPO2's that the first sign they experienced was facial twitching.

 

[dsteding]

My understanding with Nitrox and O2 Toxicity is, theres basically no warning signs once you pass 1.6 ata, and your going to more than likely meet your maker. As opposed to getting Narced, hopefully you understand that your getting loopy and start to ascend. Aside from fatique, there seems to be more room for seeing another day
with air. Thoughts?

I may be misreading this, but it seems like you are thinking that you won't get narced on nitrox. You will, to the same degree is you are on air. Nitrox's advantages are increased bottom time and shorter surface intervals. As for oxtox, I think everyone else has pointed out that diving the appropriate mix and keeping to your plan can minimize that risk.