Pros and Cons of Nitrox: What are they?

[BobRussell]

On a recent dive with my wife using 32% and myself on air we compared ND time remaining when we reached 1000psi. We were both using Suunto Vipers and held a tight buddy position during the dive. My time 11 minutes, my wife had 37 left.

 

[ScubaTexas]

I don't think I articulated my question very well. What I want to know is whether on the same dive day, can I use my reg with a tank of air for a deeper dive, and then for the 2nd dive that day, switch the reg (used earlier with air) to a tank of nitrox (<40%)? I have seen a DM do that recently and did not know if that was correct and safe.

 

[H2Andy]

yes, perfectly safe. or at least i hope it is....

 

[MechDiver]

I don't think I articulated my question very well. What I want to know is whether on the same dive day, can I use my reg with a tank of air for a deeper dive, and then for the 2nd dive that day, switch the reg (used earlier with air) to a tank of nitrox (<40%)? I have seen a DM do that recently and did not know if that was correct and safe.

I would use the nitrox for the first dive, depending of course on how deep you were going and what kind of EAN was available.

 

[mtiffee]

You can use your reg for air and enriched air all day as long as you follow the manuf. recommendations and you're using a mix less than or equal to 40%. Above 40%, you need to have equipment dedicated for enriched air use.

 

[MikeFerrara]

[*]Various nitrox blends allow for even smaller cylinders and more efficient gas usage when diving rebreathers.
[/list]

Can you explain this?

 

[ScubaRon]

The only advantage of Nitrox is a longer bottom time. Contrary to what some dive shops tell you Nitrox is not proven to be safer than air. Although it reduced the chances of DCS somewhat, it also introduces other risks (oxygen toxicity being the main one) and the overall accident rate of Nitrox divers is significantly higher than that of air divers. This does not necessarily mean that Nitrox would be unsafer either: Nitrox is probably more often used by (tec) divers who do higher risk dives.

IMO you should use Nitrox only if it gives you significant gains in actual bottom time (increasing your NDL from 45 to 65 minutes is meaningless if you have only 40 minutes of gas!) and it fits your diving depths.

Regarding the interchangeability of regs, hoses and SPGs between air and Nitrox, this has been discussed heatedly in several occasions. Virtually all manufacturers will warn against it. This includes of course some CYA, but...there still must be a reason for CYA. At the same time there are quite a few divers that do it. The problem is that it is difficult to measure the effects: it is unlikely that your reg will explode, but repeated combustion could cause significant wear on your equipment.

 

[Hemlon]

I'm relatively new to diving but there seems to be a bit of elitism when it comes to Nitrox.

Are divers who DON'T dive with enriched air looked down upon as less experienced/educated/etc?

 

[MechDiver]

I'm relatively new to diving but there seems to be a bit of elitism when it comes to Nitrox.

Are divers who DON'T dive with enriched air looked down upon as less experienced/educated/etc?

Hardly. You can have a nitrox cert right out of openwater. I have never seen any elitism with nitrox.

MD

 

[H2Andy]

if anybody does that, they deserve to be smacked around.

but then again, there are some types of people who will look upon anything as
an excuse to look down on others. i try to avoid them at all costs.