Selachimorpha
Contributor
Hi there,
There is a question I would like to open up to discussion regarding Nitrox.
I am a full time diving instructor and dive guide. For me this means that I do about 50 to 60 dives a month on average. I will normally dive for 6 days during each week and have one dry day, but sometimes it ends up being longer without time out of the water. If I am guiding I tend to do more dives than while I am teaching, so it varies a lot. Guiding I am normally doing 3 a day.
I use Nitrox 32% on every dive. The maximum depth of these dives is 30 meters, so Nitrox 32% is an ideal gas for this application. I have worked at other dive operations in other countries in the past where there was no or very limited Nitrox available. Where this was the case I was doing the same kind of diving on air, and let me tell you that Nitrox really makes a huge difference. Now I am diving to the air NDLs breathing Nitrox and I feel a whole load better, something you don't realise until you experience the change for yourself. I am refering to this strictly from the perspective of a pro doing the volume of dives that I am, it makes a massive difference. So far, so good!
However, recently I have begun thinking about my lungs. I am a PADI Enriched Air Nitrox instructor qualified to train people in the use of enriched air nitrox with an oxygen content of up to and including 40%. So in this course we learn to track our oxygen exposure based on the DSAT Oxygen Exposure Table (I think thats what it's called, I don't have it to hand, its the back of the white EAD table). PADI/DSAT informs us on this table that our exposure should not exceed 100% in 24 hours. We can calculate what % we are currently at by calculating the Partial Pressure of the Oxygen for a given depth and seeing how much time we have spent at that depth. Now if you are doing normal recreational dives, and you calculate your exposure it is nearly impossible to get anywhere near 100%. You have to spend a lot of time at significant depth (ie at high partial pressures of oxygen) and normally air consumption or even nitrogen loading is the limiting factor during a day's diving.
Now, PADI/DSAT says in 24 hours, no more than 100%. But for me where do those 24 hours end? If I dive 3 dives every day, for a week or maybe to, is each day a new one?
Of course I will continue to use Nitrox, the benefits with regard to Nitrogen are immense, I just wanted to put this out as something to consider. Would it be good to maybe a day without Nitrox every once in a while? Does it make no difference? As with other things in diving, what we are taught sometimes goes out the window when you start diving nearly every day of the year. Just interested to hear people's opinions, perhaps some of the medical people on this board, maybe some of the tech divers (those on Rebreathers must know much more about oxygen than me!).
Many thanks in advance for any replies (sorry about the long post)!
There is a question I would like to open up to discussion regarding Nitrox.
I am a full time diving instructor and dive guide. For me this means that I do about 50 to 60 dives a month on average. I will normally dive for 6 days during each week and have one dry day, but sometimes it ends up being longer without time out of the water. If I am guiding I tend to do more dives than while I am teaching, so it varies a lot. Guiding I am normally doing 3 a day.
I use Nitrox 32% on every dive. The maximum depth of these dives is 30 meters, so Nitrox 32% is an ideal gas for this application. I have worked at other dive operations in other countries in the past where there was no or very limited Nitrox available. Where this was the case I was doing the same kind of diving on air, and let me tell you that Nitrox really makes a huge difference. Now I am diving to the air NDLs breathing Nitrox and I feel a whole load better, something you don't realise until you experience the change for yourself. I am refering to this strictly from the perspective of a pro doing the volume of dives that I am, it makes a massive difference. So far, so good!
However, recently I have begun thinking about my lungs. I am a PADI Enriched Air Nitrox instructor qualified to train people in the use of enriched air nitrox with an oxygen content of up to and including 40%. So in this course we learn to track our oxygen exposure based on the DSAT Oxygen Exposure Table (I think thats what it's called, I don't have it to hand, its the back of the white EAD table). PADI/DSAT informs us on this table that our exposure should not exceed 100% in 24 hours. We can calculate what % we are currently at by calculating the Partial Pressure of the Oxygen for a given depth and seeing how much time we have spent at that depth. Now if you are doing normal recreational dives, and you calculate your exposure it is nearly impossible to get anywhere near 100%. You have to spend a lot of time at significant depth (ie at high partial pressures of oxygen) and normally air consumption or even nitrogen loading is the limiting factor during a day's diving.
Now, PADI/DSAT says in 24 hours, no more than 100%. But for me where do those 24 hours end? If I dive 3 dives every day, for a week or maybe to, is each day a new one?
Of course I will continue to use Nitrox, the benefits with regard to Nitrogen are immense, I just wanted to put this out as something to consider. Would it be good to maybe a day without Nitrox every once in a while? Does it make no difference? As with other things in diving, what we are taught sometimes goes out the window when you start diving nearly every day of the year. Just interested to hear people's opinions, perhaps some of the medical people on this board, maybe some of the tech divers (those on Rebreathers must know much more about oxygen than me!).
Many thanks in advance for any replies (sorry about the long post)!
