nitrox downsides

[Scuba-guy]

I scuba dive more than any of you do, around 2 and a half hours per day150 days a year and my opinion is its just for dumb suckers, wanna be scuba nerds and the like. Just something to sell to the dumb tourists. They will pay for nitrox but won't tip the DM, so it's a way to milk them for more cash.

 

[gamon]

You "must" analyze the contents of your cylinder before diving with it. You "must" monitor your oxygen exposure.

Whenever I see this statement I shake my head because upon deeper analysis it makes no sense when viewed in isolation.

If you're diving a rental tank from an op that also supplies Nitrox, you are incurring a similar risk in that you could very well be diving a tank full of nitrox and are exposed to potentially more danger than getting a nitrox blend that is a bit different from what you expected.

Yet air divers are not trained nor expected to analyze their air tanks.

 

[LFMarm]

Is it possible to exceed 24hr CNS clock with just recreational diving, using only 32% Nitrox?

For rec diving, it's possible but quite hard. Your MOD for EAN32 is 34m / 110ft. If you are doing recreational dives with GF 50/60, you get an average depth for each dive of ~22m / 72ft which is pO2 = 1 bar. The max 24h O2 exposure at 1.0 is 300 mins. Not impossible but unlikely.

If you do technical dives, it's quite easy to go above CNS 100%. You just need 1 dive with bottom time of ~60min at 34m with switch to 50% and O2 during deco and you get to CNS of 100% with a runtime of 105 mins. Beware that many technical divers don't regard CNS as a hard constraint. It's not unusual to do CC dives with CNS exceeding 200 or 300%.

 

[gamon]

For rec diving, it's possible but quite hard. Your MOD for EAN32 is 34m / 110ft. If you are doing recreational dives with GF 50/60, you get an average depth for each dive of ~22m / 72ft which is pO2 = 1 bar. The max 24h O2 exposure at 1.0 is 300 mins. Not impossible but unlikely.

Your example only covers the scenario where the diver stays within the MOD of the selected blend. That wasn't specified in the question.

 

[LFMarm]

Your example only covers the scenario where the diver stays within the MOD of the selected blend. That wasn't specified in the question.

I don't assume the diver wants to exceed a clear safety guardrail. Oxygen toxicity is one of the worst things that can happen underwater and nobody should exceed their gas MOD.

 

[arkstorm]

The only downside of nitrox is that you need to know how to use it safely.

But the same can be said for scuba diving in general.

There is no downside otherwise.

 

[gamon]

I don't assume the diver wants to exceed a clear safety guardrail.

It can happen unintentionally for several reasons. But that's irrelevant, again you're answering a question while changing the parameters of the question.

 

[Blackcrusader]

hi I just got my nitrox cert and can't find any reason not to dive nitrox vs air. aside from the MOD and slight extra cost is there any reason not to dive nitrox?

Yeah I was just diving in the Maldives where many dives are deep dives ie 35m to 50m so you won't be using nitrox for those dives.

Thresher sharks look great cruising the sea floor at 55m depth.

 

[davehicks]

If Nitrox is available, it is more important for the person diving air to know how to analyze and to analyze their tank!
So for me , the only drawback is deep diving.
I too get less fatigued after a full day of diving with Nitrox. However, many say it is a placebo effect.
Technically it could be possible to hit a max on 24hr CNS clock for oxtox. It has never happened to me over years of diving Nitrox even with 4-5 dives a day. So I will pose a question for the board - I know there are several guys here who are mathematically oriented. Is it possible to exceed 24hr CNS clock with just recreational diving, using only 32% Nitrox?

Realistically, no. This is not a real world problem. You would really have to work hard to get anywhere close.

 

[gamon]

Yeah I was just diving in the Maldives where many dives are deep dives ie 35m to 50m so you won't be using nitrox for those dives.
]

You might not use Nitrox on a 35 meter dive but I sure would along with a boatload of other divers.

The MOD of EAN36 at 1.6 is 34 meters and that depth is within the typical range of where divers will get the largest benefit of nitrox as compared to air.