Hey guys,
I'm going to be diving the Oriskany in a few weeks with a dive group and we will be diving nitrox. I've been certified to use it for over 2 years but have never found the opportunity to use it (air has worked fine for all my ocean dives since we'd do a deep dive then a shallow dive, shallow cavern diving etc.) . My computer can handle nitrox and I'm familiar with the rules etc. but I think maybe during my classes I misunderstood my teacher and just would like some clarification.
My instructor said the limit for PPO2 is 1.6. Now is that limit tied to the same limit as your O2 clock? Let me see if I can explain what I thought he meant and then what my confusion is.
When I first took the class, my understanding was PP02 1.6 was THE limit. If you hit 1.65 you instantly black out from OxTox. This was seperate from your O2 clock where if you reached 100%+ of your O2 clock limit, you'd black out from OxTox. They were two seperate ways to croak....for lack of a better term lol.
Now that I'm thinking about it. What if it's your first dive of the day on nitrox and you go straight to the bottom and hit PPO2 1.65 for say 1 minute and come back to a level where your PP02 is 1.3 or so. Is what my instructor was trying to say was "If you go below PP02 1.6 your O2 clock is used up much much faster so you consider it "instantly" using up 100% of your O2 clock because it only takes maybe 10 minutes to use it up at PP02 1.6?"
The reason I ask is we will be diving 29% O2 and at the beginning of the dive we're planning on touching the deck at 137'. This puts me at a PP02 of 1.58. We would only stay for a minute or two and then go hang out around 110' and shallower. Now I can have my computer beep at me if I were to hit PP02 1.6, but if something goes wrong (heaven forbid) and I get distracted for a second or take a second to become neutrally bouyant and accidentlly go slightly over PP02 1.6 I'm not going to black out right?
Sorry if it's a stupid question, just like to be very prepared for things (taking my rescue diver classes this weekend, I guess it's rubbing off on me already
).
Thanks for your responses in advance!
Jim
I'm going to be diving the Oriskany in a few weeks with a dive group and we will be diving nitrox. I've been certified to use it for over 2 years but have never found the opportunity to use it (air has worked fine for all my ocean dives since we'd do a deep dive then a shallow dive, shallow cavern diving etc.) . My computer can handle nitrox and I'm familiar with the rules etc. but I think maybe during my classes I misunderstood my teacher and just would like some clarification.
My instructor said the limit for PPO2 is 1.6. Now is that limit tied to the same limit as your O2 clock? Let me see if I can explain what I thought he meant and then what my confusion is.
When I first took the class, my understanding was PP02 1.6 was THE limit. If you hit 1.65 you instantly black out from OxTox. This was seperate from your O2 clock where if you reached 100%+ of your O2 clock limit, you'd black out from OxTox. They were two seperate ways to croak....for lack of a better term lol.
Now that I'm thinking about it. What if it's your first dive of the day on nitrox and you go straight to the bottom and hit PPO2 1.65 for say 1 minute and come back to a level where your PP02 is 1.3 or so. Is what my instructor was trying to say was "If you go below PP02 1.6 your O2 clock is used up much much faster so you consider it "instantly" using up 100% of your O2 clock because it only takes maybe 10 minutes to use it up at PP02 1.6?"
The reason I ask is we will be diving 29% O2 and at the beginning of the dive we're planning on touching the deck at 137'. This puts me at a PP02 of 1.58. We would only stay for a minute or two and then go hang out around 110' and shallower. Now I can have my computer beep at me if I were to hit PP02 1.6, but if something goes wrong (heaven forbid) and I get distracted for a second or take a second to become neutrally bouyant and accidentlly go slightly over PP02 1.6 I'm not going to black out right?
Sorry if it's a stupid question, just like to be very prepared for things (taking my rescue diver classes this weekend, I guess it's rubbing off on me already
).Thanks for your responses in advance!
Jim
