Nitrox course. What's the point?

[Divin'Papaw]

Diving nitrox is not safer than air if both are dived to NDL.

Yes and No. No in that what matters most is your NDL and your ascent practices. Yes in that if you do the same dive on Nitrox vs Air your nitrogen loading will be less and thus, at least in theory, the dive will be safer. This is magnified if doing multiple dives. With that said that is really a hypothetical situation because rarely are you doing the exact same dive if using Nitrox. You are staying longer and may be coming just as close or closer even to your NDL than if you'd used air. In that instance the Nitrox dive may be "less safe" than the Air dive.

The primary reason for using recreational Nitrox is to increase your NDL. That is seen most clearly on repetitive dives in the 40-100' range using something like EAN36.

But with the hypothetical situation aside I tend to agree with you. The whole theory of NDL supports your view. Dive within them and pay attention to your ascent practices and the gas you are using is irrelevant to the level of safety of the dive.

 

[Celt]

Yes and No. No in that what matters most is your NDL and your ascent practices. Yes in that if you do the same dive on Nitrox vs Air your nitrogen loading will be less

Stop moving the goalposts. I said nitrox is not safer than air if both are dived to NDL, the nitrogen loading is the same.

 

[Divin'Papaw]

Stop moving the goalposts. I said nitrox is not safer than air if both are dived to NDL, the nitrogen loading is the same.

Not moving any posts. Just adding discussion. Sorry if that upsets you but this is ScubaBoard. That's what we do here. It is possible for Nitrox to be safer than Air even within NDL if by "safer" we mean less nitrogen loading.

 

[Gareth J]

Diving nitrox is not safer than air if both are dived to NDL.

See Page 17

 

[tursiops]

Not moving any posts. Just adding discussion. Sorry if that upsets you but this is ScubaBoard. That's what we do here. It is possible for Nitrox to be safer than Air even within NDL if by "safer" we mean less nitrogen loading. But it is a pretty hypothetical situation.

See page 17, or post #176, which has important information in it:

It should be remembered
For dives using an air table (computer setting), it is safer using Nitrox than air.
For dives using Nitrox using the optimum Nitrox table (computer setting), the risk is the same when diving to the NDL limits. [1]


[1] DDRC have said, it is far safer to get a bend on Nitrox than Air. The prognosis for a full recovery for a diver who was bent on Nitrox is better than for the diver bent on Air. I believe, in part this is due to the effect of the additional oxygen saturation in the tissue surrounding or down stream of the bubble, increasing the time before tissue is damaged due to oxygen starvation. Also the additional oxygen increases the Nitrogen gradient, increasing the potential for reducing any 'bubble' faster. (In much the same way as oxygen is the first aid treatment for a bend and should be given at the earliest opportunity, the earlier Oxygen is administered, the better the prognosis.)

 

[MichaelMc]

Stop moving the goalposts. I said nitrox is not safer than air if both are dived to NDL, the nitrogen loading is the same.

Well..., If you dive each to NDL then do a standard ascent and safety stop, the nitrox will do more off-gassing than the air will. So safer when you surface.

But my diving is limited by N2 loading, gas, cold tolerance and desire for lunch. Nitrox brings the later three to the front as what brings me up, meaning I have less N2 loading, always a good thing.

 

[Celt]

Not moving any posts. Just adding discussion. Sorry if that upsets you but this is ScubaBoard. That's what we do here. It is possible for Nitrox to be safer than Air even within NDL if by "safer" we mean less nitrogen loading.

That’s my point, the nitrogen loading is the same if there both dived to their respective NDL and for rec diving nitrox has the added risk of a higher PO2 than air

 

[Divin'Papaw]

That’s my point, the nitrogen loading is the same if there both dived to their respective NDL and for rec diving nitrox has the added risk of a higher PO2 than air

The added ‘risk’ is minimal if the PPO2 is kept within guidelines and the ‘risk’ is offset by real benefits.

 

[Divin'Papaw]

That’s my point, the nitrogen loading is the same if there both dived to their respective NDL and for rec diving nitrox has the added risk of a higher PO2 than air

Also as has been pointed out on this thread the nitrogen loading is not identical between the two gases even if both are used within NDL.

 

[Celt]

Also as has been pointed out on this thread the nitrogen loading is not identical between the two gases even if both are used within NDL.

If you stay at depth for the max allowable time for nitrox or air the nitrogen loading is exactly the same. Why do you think you get longer bottom times on nitrox?