nitrox

[MATTBIN]

Originally Posted by Lazlo

Just to correct something (sorry if I misunderstood your post Matt): the PADI basic nitrox does not require any dives - the standard was changed. That makes it cheaper than before obviously.

I thought I had heard that which is why I put "was/is" cheaper than Padi Basic Nitrox, not up with current costs but I am happy you know and posted correct info. No problem.

Matt

[B]

when we did our padi nitrox we had 2 dives included. I know some people on here argue that they are not necessary, I strongly disagree... if I had not felt the effect of diving on nitrox I would not have continued to do so and use it to its full effect ie. when doing a 3 dive day, 2 dives on nitrox and 1 on air... much much less tired...

Nitrox has got to be one of the best courses we ever did...

[MATTBIN]

Originally Posted by The Prices

when we did our padi nitrox we had 2 dives included. I know some people on here argue that they are not necessary, I strongly disagree... if I had not felt the effect of diving on nitrox I would not have continued to do so and use it to its full effect ie. when doing a 3 dive day, 2 dives on nitrox and 1 on air... much much less tired...

Nitrox has got to be one of the best courses we ever did...

When I did my TDI course the Instructor did two dives with me/us anyway but didnt charge for it. I was led to believe that was quite normal (for TDI anyway). I felt the TDI thing was less commercial (than Padi is rumoured to be) and more one diver helping another with costs minimized as much as possible. Having said that the guys that did my OW /AOW werent money grabbing bandits either.

Matt

[Rob Dobson]

I would find a decent instructor (BTW Mark Powell is superb and is on this board), discuss what you are looking to do dive wise over the next year or so and do the most appropriate course.

You seem to be asking about basic nitrox courses but depending upon the sort of things you want to do it might be an idea to do a combined basic & advanced nitrox course and possibly even combine them with a deco course.

If you are purely looking at NDL recreational fishy stuff then a basic course would probably fit but still do it with a *good* instructor (I've found the quality of training can vary enormously even within the same agency guidelines).

[beanz1]

Originally Posted by scapaman

but tell me what does breathing nitrox do ? stop you getting bent ?
lessen your deco stops?

im no expert but here goes (in a nut shell)

breathing air is 21% oxygen 79% nitrogen.

enriched air is air with an oxygen content higher than 21%.

getting bent is caused by the body absorbing too much nitrogen.

this is where the RDP comes in and set limits for no stop diving.

nitrox/enriched air has more oxygen therefore less nitrogen as a result you breath less nitrogen and your body absorbs less nitrogen.

therefore your no stop time is extended because it takes longer to reach the maximum nitrogen loading in your tissue for no stop diving.

there are others factors involved like oxygen exposure and partial pressures but you will learn all about this on your chosen course.

i personally did the padi enriched air diver speciality and found it both informative and rewarding and i have no doubts that it will be worth every penny

like i said im no expert and please feel free to correct any mistakes ive made both for scapamans and my benefit

[Lazlo]

Originally Posted by beanz1

getting bent is caused by the body absorbing too much nitrogen.

Hmm, not quite. DCS is caused by the nitrogen leaving your tissues too fast, and causing bubbles, not necessarily because you have taken on lots of nitrogen. When you get to certain limits, it becomes impossible to safely ascend all the way to the surface without stopping - that's when the dive changes from a "no-stop" dive to a "decompression" dive. I use the quoted terms in their generally accepted sense, some people view all dives as decompression dives, but that's by the by.

Using enriched air, means that you reach those limits after a longer time (everything else being equal).

Otherwise fine

[CALLISTO]

Originally Posted by scapaman

thanks for the advice and once again you`ve come up trumps i will take on board every ones coments.
but tell me what does breathing nitrox do ? stop you getting bent ?
lessen your deco stops?
cheers and thanks....

There is no magic gas that Stops you getting bent ...proper dive planning Gas management and skills do that !!!!!

Its always a good Idea to lower the percentage of N2 in any mix wether 02 or He ..Its not that He and 02 is great for you ..its more high partial pressures of N2 are NOT

Andrew

[Lou]

Originally Posted by The Prices

when we did our padi nitrox we had 2 dives included. I know some people on here argue that they are not necessary, I strongly disagree... if I had not felt the effect of diving on nitrox I would not have continued to do so and use it to its full effect ie. when doing a 3 dive day, 2 dives on nitrox and 1 on air... much much less tired...

Nitrox has got to be one of the best courses we ever did...

Please don't expect this to happen!

I have never been one to feel the benefit on nitorx, although i do use it alot. A good ascent, or enough deco makes a huge differnece. Water temp makes a huge difference. even whether I feel seasick or not can make a huge difference, but just breathing nitrox? No.

Of course, it all depnds how you use it and what sort of dives you are comparing it to on air.

It is still a very, very good course to take.

[frosty the snowman]

Originally Posted by scapaman

thanks for the advice and once again you`ve come up trumps i will take on board every ones coments.
but tell me what does breathing nitrox do ? stop you getting bent ?
lessen your deco stops?
cheers and thanks....

Nitrox works in two ways. Firstly the increased oxygen content of your breathing gas means that the amount of nitrogen is proportionately reduced leading to comparitively reduced tissue saturation in a given time. The REAL way nitrox works is that by 'requiring' extra gear with expensive stickers and different coloured ends and filled with expensive ultra clean gas, it costs more so you may not be able to afford to dive as much and the more you stay out of the water, the safer you are. Simple!

[Woz]

There was a study done recently in the USA and it found that feeling better after breathing nitrox was purely a placebo effect. They had lots of cylinders, all unmarked, some with and some without nitrox, and they asked how they felt after the dive. There was no difference between them.

Anyway.

The benefits of nitrox are inthe 25-40m range, doing miltiple dives over multiple days. For a single day's diving, air is perfectly fine with maybe a sling of 50% to huff on while ascending. It's also the cheapest way to dive nitrox, even if you don't accellerate the deco and just dive it like you were on air, adding that margin of safety on the way up. Ascending nice and slow also helps- I try not to get any bars on the ascent-o-meter on my computer.

Links to the US article here:
http://www.kitfondle.co.uk/images/nitrox/page1.gif
http://www.kitfondle.co.uk/images/nitrox/page2.gif
http://www.kitfondle.co.uk/images/nitrox/page3.gif
http://www.kitfondle.co.uk/images/nitrox/page4.gif