Feb12
Using Nitrox
Using nitrox is a no brainer unless you are going deep enough to exceed the MOD of the mix. These days membrane nitrox units are getting very common, even on liveaboards, so it is very cheap to use the stuff, in fact it is often free.
The benefit of nitrox is very obviously that you absorb less nitrogen for a given dive. However there is a second benefit. The lower nitrogen PP in your lungs on ascent mean that you have the effect of accelerated decompression. There is a bigger gradient between your nitrogen tissue tension and your lung PP so the nitrogen is sucked out of you.
The greatest benefit is on multiple dives per day and multi day diving. It is not uncommon for divers to do 6 or 7 dives in a day on Bonaire in perfect safety. One trick I use is to keep an eye on my computer to keep the remaining ND time to, say, 20 minutes. If it goes below this I ascend a bit and the number goes back up. This way I am keeping a constant and known extra margin of safety.
The reason you get a thick head after diving is because of gas micro nuclei in your brain. If you have a brain scan you will probably find that you have lesions. Nitrox reduces this because it creates the same effect of ascending more slowly. Of course you could achieve the same effect by better managing your ascent rate, especially for the critical last few metres. People who do a 3 minute safety stop and then fin up are asking for trouble and obviously don’t understand the basic physics of what they are doing. It is the percentage change in pressure that matters not the number of metres. I am perfectly happy to fin straight up from 50 metres to 45 but from 5 metres to the surface it will always be a couple of minutes or more.
The nitrox course is very simple, you already know how to breathe and how to dive. All you really need to learn are a bit of physics, the poisonous effects of oxygen and the discipline of always knowing what you are breathing on a dive. These days you can use nitrox from your very first dives and the benefits are so great that this is an excellent thing.
I only use air when nitrox isn’t available or for the very rare occasions when I want to do a deep air dive. I have been told that at every depth there is a better gas to be breathing than air.
The benefit of nitrox is very obviously that you absorb less nitrogen for a given dive. However there is a second benefit. The lower nitrogen PP in your lungs on ascent mean that you have the effect of accelerated decompression. There is a bigger gradient between your nitrogen tissue tension and your lung PP so the nitrogen is sucked out of you.
The greatest benefit is on multiple dives per day and multi day diving. It is not uncommon for divers to do 6 or 7 dives in a day on Bonaire in perfect safety. One trick I use is to keep an eye on my computer to keep the remaining ND time to, say, 20 minutes. If it goes below this I ascend a bit and the number goes back up. This way I am keeping a constant and known extra margin of safety.
The reason you get a thick head after diving is because of gas micro nuclei in your brain. If you have a brain scan you will probably find that you have lesions. Nitrox reduces this because it creates the same effect of ascending more slowly. Of course you could achieve the same effect by better managing your ascent rate, especially for the critical last few metres. People who do a 3 minute safety stop and then fin up are asking for trouble and obviously don’t understand the basic physics of what they are doing. It is the percentage change in pressure that matters not the number of metres. I am perfectly happy to fin straight up from 50 metres to 45 but from 5 metres to the surface it will always be a couple of minutes or more.
The nitrox course is very simple, you already know how to breathe and how to dive. All you really need to learn are a bit of physics, the poisonous effects of oxygen and the discipline of always knowing what you are breathing on a dive. These days you can use nitrox from your very first dives and the benefits are so great that this is an excellent thing.
I only use air when nitrox isn’t available or for the very rare occasions when I want to do a deep air dive. I have been told that at every depth there is a better gas to be breathing than air.
Submit to del.icio.us | Digg | Reddit | Newsvine | Furl | Yahoo! MyWeb | NowPublic
No Responses to “Using Nitrox”
Both comments and pings are currently closed.