Nitrox - What do you dive PO2 - 1.4, 1.5 or 1.6?

[KenGordon]

I'd like to see limited back gas decompression incorporated into nitrox diving, not OW, but I think it's something that can be discussed in a nitrox course, even if it is limited to 5 minutes of back gas decompression it is enough to fix most issues with diving deeper than 100ft.

Something like this perhaps?

Sports Diver - British Sub-Aqua Club

 

[Storker]

If I expect to be strenuously 'working' - dark, cold, current, etc. - I will drop my max to 1.2, 'just in case'

I'm still just following my agency's recommendations (i.e. 1.4 for diving, 1.6 for contingencies), but considering that my normal diving could be regarded as "strenuous" or "extreme" by typical blue water resort divers, I'd really like to see some more specific indications on what kind of conditions that would lead you to reduce your personal pPO2 limit below the normal 1.4bar.

 

[redacted]

1.6 is my limit but it has been a long time since I have exceeded 1.4.

 

[Superlyte27]

The commonly accepted ppo2 is 1.4 or less for the working/ swimming/ stressful portion of the dive. 1.6 is the accepted ppo2 for the restful / deco portion of a dive. A lot of other things come into play here, so these are guidelines only. These guidelines are wildly subjective by region, and depth. In Fla. diving 1.6 all the time for rec dives is fine, in the north east not so much.
YMMV
Eric

I haven't dove with a single person who would agree with this. I would NEVER tell a student this. Do not do this.

 

[KevinNM]

I haven't dove with a single person who would agree with this. I would NEVER tell a student this. Do not do this.

People have in fact died of CNS toxicity at 1.3 ATA O2.
http://www.scubaboard.com/forums/di...-limits-symptoms-post7067933.html#post7067933

 

[Nasser]

There's really no way to guarantee a lot of things in diving - individual susceptibility to narcosis, toxing out, an undeserved DCS hit or even an equipment failure. There are precautions we can take along with safe practices but we essentially have to accept a certain amount of risk that comes with the territory... particularly as one enters the realm of deco/tech diving. We may have the benefit of a certain amount of collective experience and research regarding these so called limits (CNS clock and decompression theory) - but in essence this is still very much in the theoretical domain.

FWIW I dive 1.4 on the bottom mix and 1.6 deco. If there's a little work at the bottom phase I may back off a bit and maybe add some extra time on shallow deco stops. For NDL diving I generally stick to 1.4 or sometimes 1.5 depending on the dive conditions.

 

[uncfnp]

For purely recreational dives I set the computer for 1.5 but also set my brain for the 1.4 and 1.6 MOD's. I almost never go past the 1.4 but I am aware of the other limits. And of course, with recreational dives, I never get near the single or daily limits.

 

[Jack Hammer]

Typical dives are 1.2 with a 1.4 contingency and a 1.6 for deco. The 1.2 does not "penalize" you much towards deco time vs a 1.4, but helps quite a bit on long dives to keep the overall oxygen exposure down.

 

[Basking Ridge Diver]

For purely recreational dives I set the computer for 1.5 but also set my brain for the 1.4 and 1.6 MOD's. I almost never go past the 1.4 but I am aware of the other limits. And of course, with recreational dives, I never get near the single or daily limits.

uncfnp - being from NC how do you determine your MOD then? 1.5 or 1.4 to the sand or the deck of what you want to dive or are you diving reefs?

 

[waterpirate]

I haven't dove with a single person who would agree with this. I would NEVER tell a student this. Do not do this.

I think you missed the point of post. A scuba board norm. I have witnessed this in Fla. a lot. I do not condone it. My statement was about what is accepted and what is not in rec diving, based on geographical location.
Eric