Nitrox: Which agency to use?

[DevonDiver]

Also consider the ANDI 'Complete SafeAir User' course. This goes WELL beyond the basic nitrox training, far exceeding what PADI etc teach. It's much more closely aligned to courses like 'Advanced Nitrox', but doesn't have the technical element/higher prerequisites that AN courses typically require (you can do the course at OW level). Qualification is to 50%, no deco, with depth restrictions in-line with your highest existing rec qualification.

The course is very diligent with manual calculations and tables use... and includes elements about blending, equipment etc. ANDI consider this a 'level 2' course. All Level 2 courses can be expected to be of an "advanced recreational" scope of training. Only two cylinders and up to two gases may be employed to limit the task loading. This is essentially the recreational limits that are accepted world-wide: 132 feet maximum depth, No-Stop-Required profiles, no decompression training, 1.45 PO2, 4.0 PN2 and information content of a more complete or more technical nature.

 

[drrich2]

The question I am asking on these boards is which agency should I use for a Nitrox course?

It would be useful to know some modifiers. Let's see how this applies to you.

1.) Many divers get nitrox-certified to dive EAN 32 (roughly) in Bonaire or on live-aboards diving 3 - 5 times/day so NDL's don't cramp their style, with no intention of exceeding MOD (110 feet) for the mix. They need a general overview to use it with reasonable safety and a cert. card so they can get it.

The PADI course, or another agencies' for that matter, should be fine.

2.) Some people, perhaps with a more 'engineer' type mindset, dislike 'easy' and 'superficial' courses, even if sufficient to accomplish the objective, and want more 'meat' in a course.

3.) Some people plan to progress into technical diving, and may use a nitrox mix to accelerate deco., from what I understand, and may conduct a dive over time using more than one type of gas mix.

If you want to go to Bonaire and take advantage of the 'unlimited shore diving with nitrox' package, that's one thing. If you figure to progress into technical diving with deco., that's another.

So, how to you plan to use your cert.?

Richard.

 

[Jim Lapenta]

That's actually too narrow a definition. You don't need to intend to progress into tech to want to know how to calculate MOD, EAD, best mix, or what percentage of O2 to air to obtain a desired mix. Being an informed diver who takes more responsibility for what goes into their body for a given set of circumstances is closer to the mark. IMO. And that does not require an engineer or other what some may call "geek bent" to do that. And unless you can guarantee that every tank is going to be 32% somewhere, I'd rather know what to do when I grab one that analyzes at 34% and perhaps forces me to change my overall dive plan. Not guess or blindly set the computer and go, hoping that it's algorithm matches my physiology and personal limits of conservatism.

Sent from my DROID X2 using Tapatalk 2

 

[diver_dj]

Where in NJ are you? Most of the HSA instructors around here are also PADI instructors, so they should be able to help you.

 

[KoiWatcher]

I want to thank everyone for their comments. I am sharing this information with the folks in my HSA/WWP group. Oddly enough, the solution may be as simple as not using PADI.

Now to answer some questions:

1) I have been to Bonaire, and yes that type of "recreational diving" would be typical of the reasoning for my wanting to use Nitrox - nothing tec at all.

2) I do not own own a dive computer, my mind still works just fine for the simple calculations involved, thank you.

3) Jim: I think she liked the way that our instructors used what some folks would consider scenario based training, it appealed to how she prefers to learn. Instead of doing one skill, checking it off, and moving on (we did it that way in the pool sessions), the instructors created scenarios of varying complexity for the open water portion which required demonstrating several skills to successfully complete. In the unconscious diver scenario for instance, one of the many PADI check boxes met would have been the surface diver tow, which you usually see treated as a separate skill. By tying it to a scenario people see a reason for doing things a certain way and as they see a benefit it tends to be retained. I do not know if this is still done and it may be very dependent on the instructors.

4) and diver_dj brings up a good point. Do current PADI dive shops and their instructors look the other way and embrace the income stream (say from selling a camera and related course), since HSA is not on PADI's approved agency list? Isn't there some type of liability issue? How does your instructor's insurance cover teaching continuing education students whose OW cert is from an unrecognized agency?

 

[Jim Lapenta]

Thanks for the extra details. I refer to what you are talking about as increases task loading. Clearing a mask once you've done it a couple times is nothing. Clearing it while also dealing with an air share while swimming is a little different and reinforces and shows why you need to be proficient. Not to just check it off on a slate. I would seriously take Jeff (Sea Cobra) up on his offer. There is absolutely no reason to stay with any agency when that agency starts failing to meet your expectations or needs.

 

[drrich2]

Jim:

I did apply reductionist reasoning to make the choices distinct, true. Granted, some rec. divers can use more understanding of nitrox; the example that springs to mind is the diver who plans a trip diving to 120 - 130 feet on North Carolina ship wrecks to see sand tiger sharks, and wants max. bottom time without exceeding a MOD.

Of course, you can check a table of MOD's, get that mix, have a custom fill done, analyze it for accuracy, enter it on your nitrox-capable (as most now are) computer and go.

Not guess or blindly set the computer and go, hoping that it's algorithm matches my physiology and personal limits of conservatism.

Tables don't take into account age, obesity, fitness level, etc..., either. Given the vague nature of our understanding of decompression illness risk factors as they apply to the individual, regardless of whether you dive air or nitrox, or use tables on a square profile dive or a computer on a multi-level or square profile dive, it makes sense for people with reason to believe themselves at much higher than usual risk to dive conservatively and not aggressively push their NDL limits, whatever tool they use to get them.

I'm not sure that reasoning is unique to diving nitrox; seems to me it's the same we have with air.

You gave an example of expecting EAN 32 & on analysis finding out it's EAN 34, and how it'd change your overall plan. That depends on diver, dive plan and location. For me shore diving Bonaire, that means EAN 32 MOD 110', EAN 36 MOD 90', I probably wasn't planning to dive over 90' to begin with and EAN 34 is somewhere between the 2 and gives NDLs at least as good as the EAN 32 the computer's set for (and my Cobalt gas % setting is easily reset if I wish). Your dive planning may be different. I'm used to 'EAN 32' running anywhere from around 31 - 35% when analyzed.

Richard.

 

[Jim Lapenta]

Wow. The shops I deal with have a +/- 1%. That much deviation would insure I always bring my own analyzer. We always mix for max depth and plan for that. And my own personal PP02 limits are 1.3 for working portion and 1.5 for deco unless something hits the fan. Then I'll accept 1.6. But that is based on my knowledge of my body and my personal risk level assessment. In addition to adding risk factors to up conservatism based on things like zero vis, temps below 50 degrees, overhead, etc., all of that plays into what I am willing to accept as a max level.
If I plan to use mix good for 110 that means I am likely going near that or wish to be able to. If I get a tank with a MOD of 90 then it means I need to come up with a new plan and possibly alter the ultimate goal of the dive. Or I check tanks until I find one with my desired mix.

 

[KoiWatcher]

Jim: Your mentioning of an air share (via octo) while swimming (a controlled surface ascent) was how i had to do it in basic open water. Only in the pool was each task singled out. I do realize that we had substantial pool time (4 hours lecture, books and video; then 4 hours pool for 3 Saturdays) compared to some programs; and HSA/WWP also required a minimum of five open water dives (most folks did 2 dives a day and ended up with 6 total, certifying on either dive 5 or 6). The extra time makes a difference. Being taught by old school jersey divers, they also supplemented the course with things like sharing a single regulator (receive reg (exhaust down), purge, puff, puff, pass back). Task loading is always an issue. As I remember from another life "When the pin is pulled Mr Grenade is not your friend!" which is also a reference to task loading. You simply learn to get it done.

 

[KoiWatcher]

A quick update:

I ran into someone who is a recent (summer 2013) HSA/WWP certified diver. Manny said his course was 3 days long over 3 weekends consisting of 3 hours class room, then a lunch, and then 3 hours pool. He still had a five dive minimum open water requirement which he did over 2 weekends. His group also completed DAN's DEMP class as an add-on, something about there being some ex-combat medics in his group and they all wanted to learn more. He did do the raise an unconscious diver scenario on his last dive before certifying. So a little less pool time, but otherwise essentially the same course I had minus the add-ons. Oddly enough, he has PADI dive shops willing to accept his HSA certification for continuing education, although I suspect this is most likely a case of the shop assuming HSA is "good" since it's been around for a long time and is well known, rather than actually contacting PADI to check.