Value in diving Nitrox?

[mrlipis]

I recently spent a week on a liveaboard diving Nitrox 32. My buddy dove Air. Our dive profiles were essentially the same. We discussed this at length and after spending $150.00 on Nitrox I found myself a little argumentative, however the more I thought about what he was saying the more I started to agree. Here is the position he took.
At no time did he ever reach nitrogen levels that would put him in the yellow and his point is, until your air consumption is so refined that you are staying down for extended times, the nitrox really doesn't benefit you. We were diving at depths of 90+ and we logged 4 to 5 dives every day. We always had a minimum of 80 minutes of surface time between dives. Although we did not spend a lot of time at depth, we generally started our dives deeper on the wall and worked our way back up. Dive times of 40 to 45 minutes with 500 psi at surface

My position was, a lower nitrogen level, regardless of what it is, would be a positive thing.

Just looking for some feedback that can support either position.

Bruce

 

[Zoomer]

Well if memory serves me correctly 90+ feet is not the optimum range for EANx... now if you where on a liveaboard and diving 4 or 5 dives a day in the 40 to 80 foot range you will than see the benefits of diving EANx... you could get all your dives in for the day diving EANx where someone diving regular air may or may not.

here is an example, both examples do mot go into safety stop:
EAN32 60ft bottom time of 70 minutes (if you can make a cylinder last that long)
Air 60ft bottom time of 47 minutes

Now if your SAC rate is good you could actually outlast (longer bottom time) a cylinder filled with air.

 

[Web Monkey]

extended times, the nitrox really doesn't benefit you. We were diving at depths of 90+ and we logged 4 to 5 dives every day. We always had a minimum of 80 minutes of surface time between dives. Although we did not spend a lot of time at depth, we generally started our dives deeper on the wall and worked our way back up. Dive times of 40 to 45 minutes with 500 psi at surface

My position was, a lower nitrogen level, regardless of what it is, would be a positive thing.

Just looking for some feedback that can support either position.

Divers using Nitrox absorb less nitrogen, giving extended bottom times.

If you're running in to the NDL on your tables or computer, then Nitrox will give you longer dives. If not, then you might as well dive air.

Some people claim to feel better diving Nitrox. AFAIK, this hasn't been scientifically tested, although that doesn't make it false either, just unverified.

Terry

 

[micklock]

The New Jersey Scuba Diver has some good info on nitrox and air.

 

[String]

Nitrox doesn't always have a use.

If youre ending dives due to NDLs more than gas consumption its useful. If you're not then it isn't.

Generally a good SI can make it less useful than it would be with a compressed schedule.

Also if some operators give a max dive time this can make you end a dive long before extended NDLs come into play.

So in short, it depends entirely on the schedule and SAC as to whether its worth the cost and effort. Anything else such as a possible increase in safety margin, less tired etc are entirely unproven and may not actually be true.

 

[Mr.X]

I recently spent a week on a liveaboard diving Nitrox 32. My buddy dove Air. Our dive profiles were essentially the same. We discussed this at length and after spending $150.00 on Nitrox I found myself a little argumentative, however the more I thought about what he was saying the more I started to agree. Here is the position he took.
At no time did he ever reach nitrogen levels that would put him in the yellow and his point is, until your air consumption is so refined that you are staying down for extended times, the nitrox really doesn't benefit you. We were diving at depths of 90+ and we logged 4 to 5 dives every day. We always had a minimum of 80 minutes of surface time between dives. Although we did not spend a lot of time at depth, we generally started our dives deeper on the wall and worked our way back up. Dive times of 40 to 45 minutes with 500 psi at surface

My position was, a lower nitrogen level, regardless of what it is, would be a positive thing.

Just looking for some feedback that can support either position.

Bruce

Less nitrogen in the system is always a good thing. Since you were both diving similar profiles with no real obligatory deco. I'd compare and contrast some benefits of diving nitrox - feeling less tired, or sleepy after dives, maybe a tad more clarity at depth? In my book, I always appreciate having just that much more energy after several dives a day.

X

X

 

[Kingpatzer]

From a safety perspective, when doing multiple dives a day, using nitrox gives a better safety margin than air all other things being equal.

However, if you're diving 80's or diving deep and don't have a very low sac rate, then the real benefits of nitrox -- longer NDL times, just aren't going to be seen.

Is it worth it?

That's a personal decision. But If you're not getting in an extra dive each day due to lower SI's, or getting more time under due to longer NDL's, then you're not getting economic value for the gas. But you are getting some margin of safety.

 

[Randy43068]

I like nitrox if I'm diving several dives in a day, or weekend for that matter. Mix depends on depth of dive or course.

 

[Rick Inman]

Well if memory serves me correctly 90+ feet is not the optimum range for EANx...

You don't have to remember. Usually they have banked 32%. So [(1.4 / .32) -1] * 33 = what?? We can all easily do the math, but 90'+ feet is just fine.

 

[Mack Diver]

I think the extra safety margin alone gives the Nitrox a positive edge over air. Improving your SAC rate, thereby extending dive time will increase the benefit. Less fatigue, increased clarity at depth and any other unproven aspects of Nitrox are just bonus.