Nitrox After 45

[leadweight]

A few people have told ne that DAN recommends that all divers over the age of 45 use Nitrox for all dives. I searched the DAN site and could not find this. Does anyone have a link to this advice or know what the details are regarding this announcement?

I have done a search of this forum regarding the additional safety of using Nitrox and found the results to be somewhat less than clear. Anyone want to comment on this? I think it would be fair to assume that any safety benefit regarding Nitrox would be within the context of diving Nitrox on a profile that could be completed within the no-stop linits on air. Or am I wrong?

 

[MikeS]

I’m only forty-four so I’m not sure this applies to me, but I only dive Nitrox when I wear gloves on shallow reef dives.

Mike

 

[dsgobie]

Sure it would be "safer" if you were to dive nitrox. If you were to dive Nitrox on air tables with respect to MOD's, PO2, and exposure limits. But to dive a profile of say 60fsw on EAN32 for the max no stop time is no safer than doing 60fsw for the max no stop time on air.

 

[Big-t-2538]

Nx is referred to as geezer gas....there have been discussions on this before...Pug knows a bit more about it than I do, but diving Nx at shallow depths (less than 80 ft.) is way safer than air. Not near as much nitrogen loading reduces the risk of DCS.

 

[Big-t-2538]

Checkout this thread...some discussion in there about this


http://www.scubaboard.com/showthread.php?s=&threadid=18911

 

[Saturation]

Hi LW:

This is likely an error. Divers of any age can dive with compressed air on NSL dives.

Tom Mount, president of IANTD, is over 60 years old and dives trimix rebreathers into decompression to depths in excess of 300'.

Age is not the issue, but fitness to dive is, physically and mentally.

Nitrox offers safety if dove within air tables to reduce N2 exposure but such a safety factor is not age dependent.

In those who qualify, Triox offers potentially more safety, since in addition to the nitrox component, the He portion mobilizes faster than N2 and is more predictable for offgassing.

Hypothetically, aging divers may have issues regarding tissue perfusion. Thus, they would require slightly longer periods to off gas. The duration is unknown, as this is purely hypothetical. However, regardless aging divers would benefit from formal decompression to rid themselves of inert gases even in NSL dives, such as in breathing 02 at the safety stop instead of back gas.

leadweight once bubbled...
A few people have told ne that DAN recommends that all divers over the age of 45 use Nitrox for all dives. I searched the DAN site and could not find this. Does anyone have a link to this advice or know what the details are regarding this announcement?

I have done a search of this forum regarding the additional safety of using Nitrox and found the results to be somewhat less than clear. Anyone want to comment on this? I think it would be fair to assume that any safety benefit regarding Nitrox would be within the context of diving Nitrox on a profile that could be completed within the no-stop linits on air. Or am I wrong?

 

[leadweight]

What I am lookin for is not whether Nitrox offers a margin of safety simply based on the logic that nitrogen exposure is reduced below what would result from using compresssed air on the same dive, but whether there is a measurable reduction in injuries.

In other words, is there additional safety in practice, or only in theory?

Thanks for the advice on older divers.

 

[Stone]

leadweight once bubbled...
What I am lookin for is not whether Nitrox offers a margin of safety simply based on the logic that nitrogen exposure is reduced below what would result from using compresssed air on the same dive, but whether there is a measurable reduction in injuries.

In other words, is there additional safety in practice, or only in theory?

Thanks for the advice on older divers.

If I dive air for 35 minutes (until I am one dot in the yellow), and on the next day dive Nitrox for 45 minutes (until I am one dot in the yellow), I believe I have traded my margin of safety for increased bottom time. I would surmise that uneventful dives like these are equivalent as far as risk.

However, if an air diver and a Nitrox have an "event" 35 minutes into the same dive, the air diver is on the edge of his NDL, while the Nitrox diver still has 10 minutes. That's 10 minutes to solve a problem without incurring a deco obligation, or less N2 if he has to do an emergency ascent.

I suppose a case could be made that there is a built-in margin of safety, just because of the possibility of unforeseen events.

 

[Saturation]

Its theoretical.

There is not enough data collected to say nitrox is "safer" than air for lowering a risk of DCI.

Divers often use nitrox to increase NSL rather than for increasing a safety margin against DCI by diving nitrox on air tables.

The 2003 DAN Accident report states there is a slight increase in 'accident' rate for mixed gas users compared to 2002, but the actual numbers are not available.

leadweight once bubbled...
What I am lookin for is not whether Nitrox offers a margin of safety simply based on the logic that nitrogen exposure is reduced below what would result from using compresssed air on the same dive, but whether there is a measurable reduction in injuries.

In other words, is there additional safety in practice, or only in theory?

Thanks for the advice on older divers.

 

[leadweight]

Thank you Saturation. That is exactly what I was looking for, and I suspected it was the answer. None the less, I see many recreational divers shelling out $120 or so for a week of nitrox on dives that don't even get close to the no stop limits for air. They all believe they are buying safety and less fatigue.

Just to see what would happen, I tried doing a week of nitrox on air nsl dives. I did not feel any difference in fatigue. Getting the tanks analyzed turned into an administrative nightmare due to an oxygen analyzer that liked to go on strike and back up units that were crashed out as well. From now on, I will be reserving nitrox for dives where the goal is extending the nsl beyond what air offers. For everybody else, its your choice.