Nitrox diving

[emoreira]

Hi, though there is a near post about nitrox, this question is different.
I'm still a new diver, with only 39 dives under my belt. I'm still an air hog diver, though I realize that I made good improvements.
I will take soon my nitrox class, so I've been reading the nitrox chapter of the NOAA book.
Nitrox gives you more bottom time as there is a lower amount of Nitrogen in the mixture.
But how is the feeling ? Does the diver breath slower or with longer pauses between each breath ?
Suppose the same AL80 tank but with nitrox. The same volume, the same pressure, but more oxygen. The lungs breath more oxygen in each breath, so the body should have a longer pause to require a new breath owing to the generated CO2. Or you will breath less mixture as in a lower volume there is the same amount of oxygen, or a combination of both things.
Is that how it works ?
Does it taste different ?

 

[tstormdiver]

There is really no difference other than more O2 & less N2. Doesn't taste or smell any different. I breathe it exactly the same way as I do air; slow, deep & steady. The biggest difference (as you will learn in your class) is watching my depth to make sure I do not excede my maximum operating depth for the mixture & the increased bottom time due to reduced nitrogen absorbsion.

 

[emoreira]

How brute "Nitros" !!
The "s" is just a few milimeters from the "x"
I cannot edit the title.

 

[emoreira]

There is really no difference other than more O2 & less N2. Doesn't taste or smell any different. I breathe it exactly the same way as I do air; slow, deep & steady. The biggest difference (as you will learn in your class) is watching my depth to make sure I do not excede my maximum operating depth for the mixture & the increased bottom time due to reduced nitrogen absorbsion.

But if I'm an air hog, should I empty the tank at the same pace or will it last longer ?

 

[Damselfish]

the tank won't last longer.

heres one old thread asking about this, there are probably others.

 

[deepstops]

But if I'm an air hog, should I empty the tank at the same pace or will it last longer ?

The body tells you when to take the next breath when your CO2 rises to a certain point. Nitrox does not reduce the rate you produce CO2 so nitrox won't "last longer".

 

[boulderjohn]

Your body takes on O2 as it needs it, and normal air provides more than it needs. Thus, the fact that there is more O2 available with each breath makes pretty much no difference.

 

[njedrn]

air is 21% oxygen... of which your body only uses about 4%. You exhale about 16% every breath, regardless of how much oxygen is in the mix you breathe. One of the more limiting factors on a dive is how much nitrogen your body absorbs during a dive. On an "air" tank you are getting about 78% nitrogen for each breath, nitrox lessens that amount by adding oxygen (thus decreasing nitrogen). For example, a popular dive mix is 32%. This means 32% oxygen, 68% nitrogen. Less nitrogen = increased bottom time, as long as you do not exceed the max depth for your mix . (This makes sense once you read about oxygen toxicity). Hope this helps.

 

[emoreira]

Thank you so much for the answers and the links.
The posts referenced were very old (one of 2003).
The statement that increases bottom time comes from NDL and not because the tank lasts more.
Experience, trim, relax, comfort, reduced effort are the answers to decrease my air consumption, and not switching to nitrox. Besides HP130 could help ....

 

[Graeme Tolton]

Thank you so much for the answers and the links.
The posts referenced were very old (one of 2003).
The statement that increases bottom time comes from NDL and not because the tank lasts more.
Experience, trim, relax, comfort, reduced effort are the answers to decrease my air consumption, and not switching to nitrox. Besides HP130 could help ....

Hp 130 Can help with bottom time, however you may reach your NDL's before you run low on gas. That is why we use Nitrox. However, A HP130 may not do you any good if you are diving with buddies who are using al80's and need to surface long before you.

The other factor with the hp130 is that when full, it is negative 12LB buoyancy! They are commonly used here in canada, but that is in combination with cold water exposure protection (drysuit or 7mm wetsuit), where the extra weight is needed.

With Nitrox, it is very important to watch the MOD of the mix that you are using.

That all being said, the direct answer to your question is that you will not get any more time out of each tank than you would from a tank full of air.