Nitrox 1.6 or 1.4

[The Chairman]

I only set my OW diving for 1.6. I rarely exceed 1.3, but boy I hate alarms under the water: it harshes my mellow. I have enough situational awareness that I don't need an alarm for that.

On my RB, I set it for 1.3 for the first three days of diving and 1.2 after that. However, I rarely dive my RB or do deco dives more than 2 days in a row.

 

[Divin'Papaw]

1.4 and I get 36% fills almost exclusively. The diving I do is typically in the 50-95’ range. 36% is perfect.

On the rare occasion I’m diving deeper, I’ll get whatever makes sense. 28-32% typically.

All my alarms are turned off, both audio & haptic. I hate alarms. I don’t need them. I’m anal about monitoring my depth & time.

 

[Moerae]

The CNS impact of 1.4 vs 1.6 is significant. The margin for error at 1.4 is pretty big, but starts to get more narrow as you hit or exceed 1.6.

Meanwhile the nitrogen uptake difference is trivial.

While no one should be freaking out about a dip to 1.6, It seems like a silly tradeoff to stress your CNS limits in order to extend your ndl by 1 minute.

I'd wager the lack of tox hits in recreational diving has a lot more to do with how rare it is for recreational divers to be diving near 1.6 then it is an indication that frequently diving at 1.6 for long periods is "safe".

 

[Dan G]

The CNS impact of 1.4 vs 1.6 is significant. The margin for error at 1.4 is pretty big, but starts to get more narrow as you hit or exceed 1.6.

Meanwhile the nitrogen uptake difference is trivial.

While no one should be freaking out about a dip to 1.6, It seems like a silly tradeoff to stress your CNS limits in order to extend your ndl by 1 minute.

I'd wager the lack of tox hits in recreational diving has a lot more to do with how rare it is for recreational divers to be diving near 1.6 then it is an indication that frequently diving at 1.6 for long periods is "safe".

That drop in Single Exposure Minutes from 45 at 1.6 to 7 at 1.65 is dramatic and eye opening. I do need some clarification, though. Shearwater's graph "Max Single Exposure Limits" does not seem to be about cumulative exposure. OTUs from the Wikipedia article do address cumulative exposure, but I cannot find where it states a maximum cumulative limit/safety limit other than the TI formula.

 

[LI-er]

I'd wager the lack of tox hits in recreational diving has a lot more to do with how rare it is for recreational divers to be diving near 1.6

I'd wager that the complete lack of any documented oxtox hits in recreational diving is due to a combination of factors but I'd say a reasonable conclusion is that using 1.6 is not something to be concerned about.

 

[tursiops]

I'd wager the lack of tox hits in recreational diving has a lot more to do with how rare it is for recreational divers to be diving near 1.6 then it is an indication that frequently diving at 1.6 for long periods is "safe".

Exactly!

 

[tursiops]

That drop in Single Exposure Minutes from 45 at 1.6 to 7 at 1.65 is dramatic and eye opening. I do need some clarification, though. Shearwater's graph "Max Single Exposure Limits" does not seem to be about cumulative exposure. OTUs from the Wikipedia article do address cumulative exposure, but I cannot find where it states a maximum cumulative limit/safety limit other than the TI formula.

OTUs and Single Exposure Units are about different ways to hurt yourself.

 

[PEDiver]

1.4 and 1.6 for deco. If on CCR it's 1.2

I'm also a big believer in standard mixes and if I'm going below 100 ft. for any substantial amount of time there's a 99% chance there's helium in my mix.

 

[tarponchik]

I set to 1.6 when I dive Nitrox repeatedly, like on a liveaboard. When this is just a single day boat 2-tank dive trip I do not change the default value 1.4, cause it won't matter.

 

[lexvil]

1.5