o2pp 1.4ata+?

[jiveturkey]

Fair enough. Tell us why.

Because too much knowledge in inexperienced hands can sometimes lead to disaster. Wasn't that what happened to Darth Vader?

 

[Kim]

Because too much knowledge in inexperienced hands can sometimes lead to disaster. Wasn't that what happened to Darth Vader?

While I agree that too much knowledge can be dangerous there is an awful lot talked about on SB that would fall into that category!
Anyone who actually understands what PPO 1.4 means - but is not certified - should also fully well realize that they shouldn't be doing things beyond their training. It is also difficult to impossible for an uncertified diver to get a mixed gas fill to start with.
Yes we have new divers here - but we also have more experienced divers who like to discuss things as well. However to address your concern and make it again very clear:

:death2: IF YOU ARE NOT TRAINED IN THE USE OF NITROX THEN THE CORRECT PLACE TO LEARN IS FROM A QUALIFIED INSTRUCTOR. IF YOU ATTEMPT TO LEARN FROM AN INTERNET BOARD THEN THERE IS A VERY GOOD CHANCE THAT YOU WILL DIE. DO NOT ATTEMPT TO DIVE BEYOND YOUR TRAINING!!!! :death2:

Fair enough?

 

[dlegros]

Subtle Kim, like it

Dom

 

[Kim]

I have my moments!

 

[Mike Veitch]

I have no problems with 1.6, SDI also teaches a 1.6 (132 on 32%), just so happens to happily coincide with the ol Rec depth limit of 130 feet.
As for the O2 clock, in rec depths, like say 132 ft on a 32% mix, you would have to spend 2.5 hours in a 24 hour time period to get the O2 clock mad at you....think you may have a few Nitrogen problems before that would happen

 

[lundysd]

I'm just a beginner (received my nitrox not too long ago), but how many of yall have had o2 tox symptoms (however minor) when approaching and exceeding 1.6? Obviously I'm not talking about full on convulsions, simply because if you did you probably wouldn't be here posting , but I'm just curious as to how close to the limit some people have come without a negative outcome.

Scott

 

[Kim]

lundysd - It is very important to realize that while there ARE some symptoms sometimes before a convulsion - many times the convulsion happens WITHOUT ANY WARNING. Anyone who has had CNS OxTox symptoms is simply very lucky if they realized what it was in time to get shallower and drop their ppo2. This is really not something that you push the limits on without serious risk of dying. I would hate for anyone to get the wrong idea about the dangers of this - it is not like narcosis! Also, any answers to your question would really be meaningless as everyones physiology is different and there are no hard and fast limits. In fact an individuals own limits will also change due to all sorts of reasons - exertion levels, water temperatures, phyical condition at the time and many more. What you might get away with one day might kill you the next.

 

[cornfed]

Nitrox divers. Do you or will you ever exceed 1.4ata?
<snip>
Would you dive 32% to 120' (I have, and will)?

I won't dive 32% below 100ft. Recently I had a couple of dives planned to around 110' and I used 30%, even that made me nervous. Considering that if you convulse you've basically guaranteed yourself a trip to the morgue combined with the high degree of variability associated with that risk I just don't see point for just a few more minutes.

 

[do it easy]

I plan dives with the 1.4 "limit" and deco on 1.6. I don't think that I would plan a dive greater than 1.4. I might push the limits a bit if I dropped something, but it would have to be worth something to me to go after it. I'm not going to increase my risk for a $30 flashlight.

Regarding CNS vs pulmonary toxicity, I was under the impression that the oxygen exposure tables are for pulmonary toxicity, and that the way to avoid CNS toxicity is to not dive past the "limits". Does anyone have any concrete evidence about this?

 

[MikeFerrara]

I don't see any reason to push O2 limits. I'd rather stay on the low side with the acception being the gasses used during decompression. Even there though on long dives we take some extra insurance steps.

Above 100 ft I'd prefer to just stick with 32%. Screwing around with "best mixes" changing tables and all that just isn't worth it for a few extra minutes at depth. If I want a longer dive I just plan on a little deco and for that matter my typical ascent gives me some of that anyway.