Diving Nitrox to increase safety AND bottom time!

[AfterDark]

Apparently it's not a PADI prerequisite to do a dive with the nitrox course anymore. It's now purely a classroom course.
I'm thinking of doing my nitrox for a variety of reasons and I've already told my centre that I want to do a couple of dives using nitrox. How can you possibly really know if you've not experienced?

That's correct. I took a nitrox course a few months ago got the card. I made my 1st nitrox dive 2 weeks ago on 28%. I didn't feel any safer.

 

[graham_s]

I recenty did the BSAC Nitrox course (when I did my initial training it wasn't part of the Syllabus, now it is so I needed to do some catch up before starting my Dive Leader training)
It's classroom work, with a practical lesson on testing the mix with an analyser.
Mostly theory, with a lot of table work, and working out MOD from scratch.
As to needing a dive?
Seriously?
Can you tell physically what mix you're breathing?
I doubt it.
Once you're past the planning stage (mix/MOD/etc) it's just the same as any other dive. Plan the dive, Dive the plan.

 

[TjRjn]

I recenty did the BSAC Nitrox course (when I did my initial training it wasn't part of the Syllabus, now it is so I needed to do some catch up before starting my Dive Leader training)
It's classroom work, with a practical lesson on testing the mix with an analyser.
Mostly theory, with a lot of table work, and working out MOD from scratch.
As to needing a dive?
Seriously?
Can you tell physically what mix you're breathing?
I doubt it.
Once you're past the planning stage (mix/MOD/etc) it's just the same as any other dive. Plan the dive, Dive the plan.

Maybe you can't tell what mix your breathing - but that's the point. How do you know you can't (or can) without ever having tried? Personally I think it should be mandatory to do at least one dive with the course just to see.

 

[vladimir]

Apparently it's not a PADI prerequisite to do a dive with the nitrox course anymore. It's now purely a classroom course.
I'm thinking of doing my nitrox for a variety of reasons and I've already told my centre that I want to do a couple of dives using nitrox. How can you possibly really know if you've not experienced?

You won't "know" after you're experienced. At the risk of stating the obvious, you cannot distinguish breathing nitrox from breathing air. There is no sensory difference.

If you are capable of understanding the concepts involved, take the cheapest legitimate (agency sanctioned) nitrox course you can find, in my opinion. One without dives, probably. Online would be fine.

 

[TjRjn]

You won't "know" after you're experienced. At the risk of stating the obvious, you cannot distinguish breathing nitrox from breathing air. There is no sensory difference.

If you are capable of understanding the concepts involved, take the cheapest legitimate (agency sanctioned) nitrox course you can find, in my opinion. One without dives, probably. Online would be fine.

Your missing my point. I'm not doubting what your saying but being told something and trying it out for yourself are two different things. I believe people should always give something a go rather than taking someones word for it otherwise - you will really just never know.
I've been told by some people that using nitrox makes you feel fresher than you did before you dive and with someone like me rids, the headaches that I occasionally experience.
Do I take their word for it or do I try and see for myself. Maybe rubbish, maybe true but I don't know and won't know until I try.

 

[doctormike]

Once you're past the planning stage (mix/MOD/etc) it's just the same as any other dive. Plan the dive, Dive the plan.

One thing that you wouldn't get to do if you just did the online cert would be to actually analyze your tanks. This is a non-trivial task, and one that can be done wrong (i.e. calibration of the analyzer, correct positioning, flow, labeling tanks, logging fills). I guess you could just practice THAT and then not do the dive... but I didn't realize that now the nitrox course didn't involve any diving.

Do you mean you actively tell your students that nitrox is not safer than air? Or is it just that you're silent on the purported safety benefits, discussing only the extended bottom time?

If nitrox is only useful to extend bottom time then it would have no value to a diver with a higher SAC who's bottom time is dictated by their cylinder volume - would you tell such a student to avoid using nitrox since it would provide no benefit to them?

I'm not an instructor, but I have read a lot of these discussions here (this topic comes up frequently). And yes, that is pretty much the standard. The reason to dive nitrox is to increase bottom time for a diver who is being limited by NDLs and not by gas consumption. Until you get to that point, where your SAC is good enough that you run out of NDL before you run out of gas, the most common teaching is that there is no point to using Nitrox and assuming the potential Oxtox risks, extra fill costs, an equipment considerations.

That having been said, there are two other reasons why people want to do nitrox, even if their SAC isn't good enough to "make it worthwhile". Reduced risk of an undeserved hit, and "feeling better" after a nitrox dive (less fatigue, etc..).

There are MANY, MANY discussions of these last two points here on SB, so not much point in going through them all again, most of the threads just devolve into people insisting that they feel better after diving nitrox, and it's not something that you can really have an interesting debate about. But if you are asking the official reason for diving Nitrox, I think that most instructors would say that it is to increase bottom time for a diver who is NDL limited.

 

[vladimir]

Your missing my point. I'm not doubting what your saying but being told something and trying it out for yourself are two different things. I believe people should always give something a go rather than taking someones word for it otherwise - you will really just never know.
I've been told by some people that using nitrox makes you feel fresher than you did before you dive and with someone like me rids, the headaches that I occasionally experience.
Do I take their word for it or do I try and see for myself. Maybe rubbish, maybe true but I don't know and won't know until I try.

You can't try it after you're certified? That's why most people get the certification, so they can dive with actual nitrox. Then you'll know, and you can post and let us know.

 

[AfterDark]

You can't try it after you're certified? That's why most people get the certification, so they can dive with actual nitrox. Then you'll know, and you can post and let us know.

Sure you can. I didn't dive Nitrox for 2 months or more after I got the cert.

 

[beaverdivers]

The Nitrox course can be done on-line, but the student must go thru how to analyse a tank, then actually analyse two tanks. The on-line course is completed by going over the on-line test w/ the instructor and having the student verify that they understand all the correct answers.

IMO if this process is not part of an on-line course, then the on-line course is invalid.

As far as using Enriched Air Nitrox, EAN, it does have value for divers that use their gas before reaching their No Deco Limit ( NDL ).

They are going thru their tank so quickly due to increased workload from significantly high respiration and/or heart rate.

For this reason, an Air Integrated ( AI ) dive computer that takes into account workload as part of its' algorithm is important.

As the workload increases due to high breathing rates and/or heart rates, the NDL or No Stop time on the AI computer will decrease.

This " Air Hog " needs EAN perhaps more than any diver.

 

[TjRjn]

You can't try it after you're certified? That's why most people get the certification, so they can dive with actual nitrox. Then you'll know, and you can post and let us know.

Practical experience is not required for the Nitrox specialization any more according to PADI. It's all about classroom work and calculations etc.. so in fact you can have the specialization without the actual experience. Hence my whole point!