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Scenario: You are on a wall-like dive in Cozumel, ocean side, at around 100 feet. You and your buddy (could be a spouse, real buddy, insta-buddy or just the random pairing during a dive) are at the end of the line as the group enters a swim-through to reach shallower water on the shore side of the reef.
You were looking at something closely for a bit, maybe a juvenile yellowtail damselfish. When you look back to enter the swim through and check on the buddy, that person is below you and still sinking. You estimate their depth at 130 feet which is below the MOD for the nitrox 32 you are using.
Assisting that diver (no one else is around) will result in the both of you going to around 150 feet before ascending. Assuming that you have the training and experience to assist the diver below you, do you bust the MOD limit for nitrox 32 or would you prefer to be on air?
What in the world are we arguing over here?
. . .
So why are we arguing it?
Define "need". Need for what?When I get older I'm going to give it a try. We call it "Geezer Gas" and get a kick out of
those that need it.....
There is one topic that hasn't been addressed at all in this thread, and that is Nitrogen Narcosis. Different people have different levels of tolerance to Nitrogen - some people will have very little effect even at 150 feet (below the limit for recreational diving), while others will begin to get narced at a depth as low as 100-120 feet. It seems that Nitrox, even a mix like EAN 28, which you might want for a deeper dive to 135 feet (ppO2 at 135 feet on EAN 28 would be at about 1.4; still low risk for Oxygen Toxicity with a short exposure time), by reducing PPN, will also reduce the effect of narcosis at any given depth. An alert diver unimpaired by narcosis is a safer diver. One more reason to dive Nitrox.
There is one topic that hasn't been addressed at all in this thread, and that is Nitrogen Narcosis. Different people have different levels of tolerance to Nitrogen - some people will have very little effect even at 150 feet (below the limit for recreational diving), while others will begin to get narced at a depth as low as 100-120 feet. It seems that Nitrox, even a mix like EAN 28, which you might want for a deeper dive to 135 feet (ppO2 at 135 feet on EAN 28 would be at about 1.4; still low risk for Oxygen Toxicity with a short exposure time), by reducing PPN, will also reduce the effect of narcosis at any given depth. An alert diver unimpaired by narcosis is a safer diver. One more reason to dive Nitrox.
Agreed. You do/can do so many bounces in Cozumel - I personally think it ups the risk for DCS hits on top of everything else.
I consider my using nitrox secondary insurance, and am seriously thinking of just doing 32/36 on all tanks.