Need Help with Nitrox

[ianr33]

I've got a ndl time of 39 mins at 80 ft with my computer

Sure its not set to air?

 

[ianr33]

Those tables you linked are based on a max PP02 of 1.6, which is generally only used for decompression dives... most agencies recommend 1.4 or less for non-deco dives

I'd suggest you re-read your nitrox course materials

Did you do it online?

So you would never personally use a pO2 in excess of 1.6? Might that be dangerous?

 

[Narced Out]

Thanks guys for the help. I was just in class and wanted to bring this topic up and didnt have my nitrox table with me...so i googled one. I still have my nitrox book so ill look at that when i get home. So i guess ill just stick with a 36% maybe 32% depending on what my buddy wants. I felt the need to post here because i dont want to make a life changing mistake, Im still a somewhat new diver and just trying to find where i fit..

 

[Jim Lapenta]

I'd also advise you to go and get your money back from that instructor. You should not have received a cert if you are still asking questions like this. Tables are not that hard to read and the formula is easy enough. Something seriously wrong here.

Almost as bad as my GF reviewing her nitrox materials and noticing they said to immediately start ascending with a toxing diver who is having a seizure! She knew it did not sound right and asked me.

 

[Narced Out]

Jim i asked a simple question to clarify something, im not the best with math.

 

[Jim Lapenta]

THat's just it. There is no math involved. You read the NDL next to the depth for the correct mix. Even someone challenged at math should be able to figure an NDL for a given mix. The failure is that your instructor did not realize that you needed extra help. He/she should have picked up on this immediately and done whatever was necessary to see that you clearly understood. They dropped the ball.

 

[scubadiver888]

I'd have to agree with Jim about getting your money back. There were a few people in my EAN class who weren't great with math and the instructor took the time to make sure everyone could plan their own dives.

She also made a point of the fact that YOU will be required to sign a logbook when you get an EAN mix. You will need to analyze the mix and confirm it is correct AND you will need to write down what the MOD is for that mix. She made it very clear that I am responsible for making sure the mix is right for the dive I am doing.

Additionally, asking for help here without specifying which agency you were trained under will lead to people making assumptions. PADI tells you 1.4 ppo2, ACUC goes with 1.45 ppo2, others might feel 1.6 ppo2 is fine, I've heard some tech divers say 1.2 ppo2 is best (but then they go into deco and have TOTALLY different training).

 

[Jim Lapenta]

I use 1.3 for working and 1.6 for deco.

 

[ianr33]

Additionally, asking for help here without specifying which agency you were trained under will lead to people making assumptions. PADI tells you 1.4 ppo2, ACUC goes with 1.45 ppo2, others might feel 1.6 ppo2 is fine, I've heard some tech divers say 1.2 ppo2 is best (but then they go into deco and have TOTALLY different training).

1.4 is a pretty standard MAXIMUM for bottom gas.Going to 1.5 or 1.6 for a few minutes won't kill you but its best not to plan on it.
1.6 for deco is also pretty standard

If I was doing a couple of HOURS bottom time then I would drop the pO2 to 1.2 or thereabouts, but for recreational diving or "regular" deco dives 1.4 is fine. YMMV.

 

[scubadiver888]

I use 1.3 for working and 1.6 for deco.

See, this is what I'm talking about. By working, do you mean you use a ppo2 of 1.3 if you're working as an instructor? Or do you mean if you are breathing heavy, i.e. exerting effort?