27 replies to this topic

[Greg@ihpil]

I am going to be taking the next step into Nitrox.Which agency has better skills/lesson's ,or are they about the same?

[shadragon]

SDI course outline is here

PADI course outline is here

Talk to your local instructor(s) and see who you feel most comfortable with. Which is better? I do not know as I have not taken both. However, the quality of the instructor should be a major deciding factor.

[Landlocked Dive Nut]

with Simon. There are even more agencies than the two mentioned that teach Nitrox and more advanced gas mixtures. Be comfortable with the instructor, and definitely find someone you can trust to actually TEACH you, not just shove the material your way and pass you if you pay their fee. Learn the new tables and the diving depth limits, and if you dive a computer make sure it is Nitrox-capable, and learn how to set the Nitrox mode & mix on it. Take your lessons seriously. Diving Nitrox can be just as deadly as diving regular air, if you don't do it right.

It is well worth the effort.....especially for divers not in the first flush of youth, so to speak. I got Nitrox certified last year, and it makes a HUGE difference in my energy level throughout the week of diving.

[Cold_H2O]

One more vote for the instructor being key to which course is better.

I encourage divers to interview an instructor before signing on for a class.

I almost didn't get my OW cert due to a bad instructor and a very bad situation.
When I went looking for a new class to join had one instructor tell me that he wasn't about to hold up his class or give me any special attention. If I joined his class I had better have my skills up to the level of his class.
Contacted a third instructor who welcomed me to join his class, explained that he would give me a check out on the first day and if I needed a little extra help he would provide it.

Guess which instructor I completed my OW with?????

Edited by Cold_H2O, 24 December 2009 - 11:35 PM.

[Greg@ihpil]

Thank's guy's. I agree about the instructor.It's the adage "You get what you pay for".In as much as I only have a 50+ number of Dives.I'm just now getting comfortable with my Versa Pro D/C.The download process etc.Having delt with a couple of the local Dive shops.I'll heed your suggestion's.
The other reason I asked the question,is I want to know all that I can once your into a area of Diving.I have looked at diving as a enjoyable sport,but one that you can continue to expand ones knowledge.I'll stop,this is getting to deep.

[peterbj7]

IMO neither is particularly good, as the course is very much of the "simplify it as much as possible so as not to scare away the customers". If you learn from an instructor who also teaches serious technical diving you're more likely to get a fuller, more rounded course. As a guideline - if it's in total less than a day or equivalent then it's likely to present just the basics. Certainly if you're told to remember formulae then I'd find another course.

Edited by peterbj7, 25 December 2009 - 06:50 PM.

[Greg@ihpil]

IMO neither is particularly good, as the course is very much of the "simplify it as much as possible so as not to scare away the customers". If you learn from an instructor who also teaches serious technical diving you're more likely to get a fuller, more rounded course. As a guideline - if it's in total less than a day or equivalent then it's likely to present just the basics. Certainly if you're told to remember formulae then I'd find another course.

Peterbj7, for the FYI.I have 2 shops in mind to go forward with the course.Both owners seem to indicate a day's class time and roughly $200.00.Both have a good local reputation.I,m also appreciative of Tammy's "youthful" rewards to us mature divers.I will ask 1st on the formula ?.I'm wondering,with the longer bttm time bonus,and your out with a boat of "reg air" divers.will the benifit be selfish.you get my drift??They will be waiting for you to come up.Maybe I'm making more out of this than necessary.I should just go with what ever developes.

[uwfan]

Maybe I'm wrong on this... but the shops (and I'm not sure other than doing something on an SD.com trip how you find an instructor) in my area ONLY provide the less than a day course, and typically they are at night after work (not MY best time to learn...). I may be missing ways to find an instructor other than going to shops, but that's what I've done all along. My dives with SD.com have been the best instructional settings, whether I've taken a class, used a rent-a-buddy, or just gone diving.

I learned how to use the tables, learned how to use one analyzer to analyze the nitrox, and was expected to read the material before the class started so that I was somewhat familiar with the material before the class. Was it the best class, no because I wasn't learning in my best environment, did it get the job done so I felt I understood the concepts I needed to know to use Nitrox safely, yes.

I'm not sure what you mean by others waiting for you, you would certainly need a buddy with you (I hope, unless you are solo certified). The benefit of Nitrox for me is that I don't feel completely drained after two dives in a day... I can easily do 4 or 5 dives a day over several days and still have energy, and that is priceless!

[Landlocked Dive Nut]

Greg, the extended bottom time means you can have shorter surface intervals (to purge nitrogen from your system), therefore you get more dives in during the day. The same size tank of Nitrox will still only last as long as a tank of regular air will last you underwater, so nobody will be waiting on you!

On SD trips, we are sometimes able to separate Nitrox and Air breathers, but in most cases we're all together on the same boat, so Nitrox breathers are buddied together. But, we still get the same amount of time in the water as the Air breathers when we're all diving together off the same boat. The advantage to us in this circumstance is having a very conservative safety margin for nitrogen buildup, which as we get older is a good thing!

Now, the advantage really shows up on a trip like Bonaire in March. We will do 2 morning dives off the boat, eat lunch, then do 1 more dive off the boat. Many who dive Nitrox will then do an afternoon shore dive, and then a shore night dive. That's 5 dives in one day, typically only seen on a liveaboard trip. By diving Nitrox, you have less nitrogen buildup in your system, so you can get back in the water faster -- AND have the energy to do so!

[Greg@ihpil]

Now I see how the "EXTENDED BTTM TIME " ,comes into play.a little embarrased .Like all new things ,there is a learning curve. Thank's!,uwfan &Tammy

[ArtRunScuba]

I love the "geezer gas". I formerly felt exhausted after several days on a liveaboard. But on the 36 hour ride to Cocos back in 2003, I took the course from the ship's (Okeanos Aggressor) Captain. Doing the course on a liveaboard, whether it is a SD connected instructor or an instructor or divemaster with the boat is the easiest process as you immediately put into practice what you learn. And since then, I have been able to dive almost all the dives in a week, though I still think it is a good idea to start slowly if it has been a while since you have been diving. Perhaps some of you can explain why it is so important to re-learn the tables in these computer days, but for me the bottom line is that every dive I take I consume considerably less nitrogen, at least 11 percent or more, and over several days that adds up in a meaningful way, kind of like compound interest in financial terms. One other thing that has been interesting on liveaboards is that from my observations on 13 subsequent liveaboard trips, which is a fairly decent sample, the male divers have been more easily convinced to take the nitrox course than the women divers.

[Greg@ihpil]

I love the "geezer gas". I formerly felt exhausted after several days on a liveaboard. But on the 36 hour ride to Cocos back in 2003, I took the course from the ship's (Okeanos Aggressor) Captain. Doing the course on a liveaboard, whether it is a SD connected instructor or an instructor or divemaster with the boat is the easiest process as you immediately put into practice what you learn. And since then, I have been able to dive almost all the dives in a week, though I still think it is a good idea to start slowly if it has been a while since you have been diving. Perhaps some of you can explain why it is so important to re-learn the tables in these computer days, but for me the bottom line is that every dive I take I consume considerably less nitrogen, at least 11 percent or more, and over several days that adds up in a meaningful way, kind of like compound interest in financial terms. One other thing that has been interesting on liveaboards is that from my observations on 13 subsequent liveaboard trips, which is a fairly decent sample, the male divers have been more easily convinced to take the nitrox course than the women divers.

Interesting way of putting it,"geezer gas" . The demographics as well.Who would have thought? Seeing is how I,m in the Chi twn area and looking out right now at a horizon of white stuff, it will be awhile before any diving is done here, "outside' as far as Im concerned.Yes,the OJT method , is better.

[Landlocked Dive Nut]

One other thing that has been interesting on liveaboards is that from my observations.......the male divers have been more easily convinced to take the nitrox course than the women divers.

I hate to use sweeping statements, but it is generally true that men use more air than women while diving (so they typically take in more nitrogen), so perhaps they benefit more from switching to Nitrox than their female counterparts? Just a thought.

[shadragon]

the extended bottom time means you can have shorter surface intervals (to purge nitrogen from your system)

By diving Nitrox, you have less nitrogen buildup in your system, so you can get back in the water faster

A Surface Interval (SI) allows you to off-gas between dives. While you can have a shorter SI on the nitrox tables, there is no need to rush. An SI on nitrox is just as beneficial as an SI on regular air regardless of the N2 in your blood, especially when doing multiple dives over multiple days. Nitrox is NOT a magical gas that removes all danger to DCS or other issues underwater. It actually has more danger when not used correctly.

You will continue to build N2 in your blood if doing multiple dives regardless of the percent of recreational nitrox used. You can only off-gas so much N2 at a time. Diving to the limits of the nitrox tables is the same as diving to the limits of regular air tables.

If you use Nitrox to the limits, then you are running the knives edge for DCS exposure. As you will learn, Nitrox lowers your exposure to N2, but also increases your O2 exposure. That must also be factored into your dive day and SI's help there too.

Whether on tables or computer; The longer your SI, the longer your bottom time on subsequent dives. Don't believe me? Run some simulations on your tables with a series of dives with one hour then with two hour SI's and watch the differences in Residual Nitrogen Time (RNT).

[peterbj7]

I think it's all been said. Nitrox doesn't just improve your overall safety but for most people considerably improves their comfort and fatigue levels. Even if you're on a boat where dive times are determined by other divers on air, if you're on nitrox you can maybe stay a bit deeper for longer, or you can do exactly the same dive as the air guys and feel significantly fresher afterwards. One thing that everyone agrees on is that if it's available it's almost always a no-brainer to use nitrox. It'll cost a bit more, but put that in context of your overall costs for your dive trip.

Let me just clarify what I said maybe a bit too succinctly about learning formulae. What I mean is that you should seek an instructor who will teach you to understand the material, not just to regurgitate it and pass the exam. The formulae in the PADI nitrox manual for example to me typify the worst possible approach to teaching this subject. I always tell my students not even to read that chapter until after they've completed the course to my satisfaction. Then if they wish they can look at it, and I hope will come to the same conclusion as I did when I first saw it. The other thing I always tell my students is to do all nitrox calculations in metric, converting from/to imperial outside the main calculations if they need to. The problem with using imperial is that the maze of numbers totally disguises the simplicity of what's actually going on.