If a parachute fails, you have a near-100% chance of dying.
Not even close to accurate. The person should have a reserve parachute.
---------- Post added July 24th, 2013 at 10:46 AM ----------
Originally Posted by
Ron Lee Plenty of nitrox available but I use air on my first dive.
Why?You're increasing your nitrogen loading, causing you to have shorter bottom times and less safety than if you dove nitrox for all your dives. Change the mix for the dive to the appropriate percentage but why dive air?
MOD Source:
DiveNerd - Nitrox Maximum Operating Depth (MOD) Table
Assume a ppO2 of 1.4, MOD for 32% nitrox is 111 feet and 187 feet for air.
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?
When I first heard of nitrox around the mid 90s, it was presented like snake oil. Longer bottom times and lower nitrogen absorption. I saw through that right away.
Nitrox does allow longer dive times. I use two Suunto computers which appear to be relatively conservative (lower dive times). On at least one dive, I set one computer to air and the other to the nitrox level I was using. It makes a big difference. There have been a few times when I was on air and had to ascend earlier than the group because I was bumping up against deco. I can deal with a deco obligation but still have to clear it before surfacing, so ascending and staying above the group works on those few occasions required. I still surface with the group at the same time.
Bottom line: I disagree with the notion that every recreational dive should/must be using nitrox. If others go that route, it does not bother me one bit.