Nitrox course. What's the point?

[Celt]

Are you sure? If I dive 32% and air to NDL at 100' and then start my ascent I'm betting that if I use the same ascent time and the same safety stop I will have less nitrogen at the surface with the nitrox. What do you think? If you disagree what about dives to 60 feet to NDL's using 50% and air?

That’s not true, the tables you used has calculated the assent into the dive. How is 60 feet NDL for air I don’t understand this
P.s. if you mean staying at 60 to NDL there’s no difference if you stay to the nitrogen loading limit of the gas you use. About 72 minutes for air and 4 hours for 50% O2 have to check that.

 

[Celt]

This would be true if you were magically transported instantly from depth to the surface.

You’re computer calculates the whole dive not just the bottom time

 

[BRT]

That’s not true, the tables you used has calculated the assent into the dive. How is 60 feet NDL for air I don’t understand this

Well, I don't know what tables/computers that you dive but I learned diving a table that said 60 minutes was NDL for air at 60 feet. My current computer says 55 minutes.

 

[David Novo]

Are you sure? If I dive 32% and air to NDL at 100' and then start my ascent I'm betting that if I use the same ascent time and the same safety stop I will have less nitrogen at the surface with the nitrox. What do you think? If you disagree what about dives to 60 feet to NDL's using 50% and air?

Theoretically you are correct. However, empirical studies did not find the difference in DCS incidence from Air to Nitrox, for the same non-deco dive profile, to be statistically significant.

 

[Celt]

Well, I don't know what tables/computers that you dive but I learned diving a table that said 60 minutes was NDL for air at 60 feet. My current computer says 55 minutes.

 

[60plus]

Exact oxygen % in Nitrox are nothing like as important and most of the nitrox course teaching leads candidates to believe. The values used are designed to give a very good margin of safety in recreational diving. HBOT treatment takes place using pure oxygen at up to 3 bar, in theory (as taught in nitrox class) that would be well over twice the pressure needed to kill someone, yet it does not.

 

[Divin'Papaw]

Exact oxygen % in Nitrox are nothing like as important and most of the nitrox course teaching leads candidates to believe. The values used are designed to give a very good margin of safety in recreational diving. HBOT treatment takes place using pure oxygen at up to 3 bar, in theory (as taught in nitrox class) that would be well over twice the pressure needed to kill someone, yet it does not.

If you OxTox in the chamber, which happens, you don’t drown. There is a BIG difference between high PPO2 in a chamber vs underwater.

 

[ToneNQ]

...... The values used are designed to give a very good margin of safety in recreational diving. HBOT treatment takes place using pure oxygen at up to 3 bar, in theory (as taught in nitrox class) that would be well over twice the pressure needed to kill someone, yet it does not.

The scenarios are quite different. OxTox doesn't kill you, anywhere. In the chamber the dive you carefully and bring you up if required. Spasm in the water and you'll drown. The margins are different because the consequences are different.

 

[BRT]

You’re computer calculates the whole dive not just the bottom time

Really? Your computer knows how long you are going to take to ascend? Mine doesn't know that. If I am out of time at 100' I may go to the surface or I may just go up a ways. I'm impressed that yours knows.

 

[BRT]

Theoretically you are correct. However, empirical studies did not find the difference in DCS incidence from Air to Nitrox, for the same non-deco dive profile, to be statistically significant.

Ask @Wookie about that.