For those considering the PADI Deep Diver speciality...

[DaleC]

Good reply Peter.

I remember reading Solo Diving by RVM and being somewhat disenchanted by it. Later I realized that there wasn't anything that different about solo diving that I didn't already know that could be put into a book. For deep diving to rec limits what can really be put in the book. Narcosis is the biggy and that really is a practical learning experience.
My hope would be that I had a good instructor for the course, not a good manual.

I'm in college right now and we have to take this course "Introduction to Computer Technology". For ten days I have been cruising the net during class because it is so lame (IMO) but... there are some people who are actually struggling with the material

 

[MXGratefulDiver]

I think CO2 recognition/management is equally, if not more, important ... dealing with that "I can't get enough air" feeling at 100 feet is a recipe for panic, especially in a less-experienced diver.

Of course, those topics are all related but that discussion should be part of the pre-dive curriculum.

... Bob (Grateful Diver)

 

[jbtut]

IMO advanced open water should really just involve an instructor taking you out and making you, without a book, pass another test that includes dive planing, navigation, buoyancy etc. Basically go diving with you, after you've logged 30 or 50 dives, and see if you know what the heck your doing and you remember what you learned in OW. But it's difficult to set objective standards for judging whether someone is comfortable and safe under water, and it's even more difficult to police all the dive instructors around the world to keep them from just passing anyone with $ to pay for it.

Has anyone ever failed someone or themselves failed AOW?

 

[JKPAO]

Oh yes there is ... I have occasionally run into someone who thought they could pay for my class, show up, not put any effort into it, and collect the C-card when it was over.

Most times, they do fine once we reset expectations. On two occasions I gave them their money back and suggested I wasn't the instructor for them.

... Bob (Grateful Diver)

So finding out that you could not teach them does not make them a bad student! Difficult to teach does not equal bad! (Do not read into this as me saying you are a bad teacher.) You just did not peak the "bad students'" own interests with the way you put the info out there. I do not care which agency policy is followed!

I still say there are no bad students! Everyone can attain an education, or learn all
skills needed to dive safe. You just have to figure how to pass on the info

That being said, Instructors have the info, if you can't get someone to be interested in your class you are right to turn them away or as you said reset the expectations.



See you topside! John

 

[MXGratefulDiver]

IMO advanced open water should really just involve an instructor taking you out and making you, without a book, pass another test that includes dive planing, navigation, buoyancy etc. Basically go diving with you, after you've logged 30 or 50 dives, and see if you know what the heck your doing and you remember what you learned in OW. But it's difficult to set objective standards for judging whether someone is comfortable and safe under water, and it's even more difficult to police all the dive instructors around the world to keep them from just passing anyone with $ to pay for it.

Has anyone ever failed someone or themselves failed AOW?

I have never actually failed anyone for AOW ... but I have had students who never completed the class. Mine's open-ended, so as long as you want to keep trying I'll keep working with you. But it is far more than an evaluation of someone's fitness to dive. To my concern, such a class as you describe is a waste of money ... you'd be better off just finding a good mentor or dive buddy and going diving.

But getting back to the deep diver specialty for a moment ... these are the topics I consider important ...

- Summary of the increased risks, including DCS, narcosis, hypercapnia, stress factors, and equipment-related issues

- Predispositions to the risks of deep diving (why someone might want to consider themselves not fit or not ready to go deep)

- A bit of fizzyology (what pressure does to our bodies and what we can do about it)

- Everything you didn't want to know about decompression sickness

- Understanding and managing narcosis

- Understanding and managing CO2 buildup

- Understanding and managing stress

- Equipment for deeper diving

- Dive planning for deeper diving (includes gas management, if you haven't already been exposed to that in my AOW class)

That's the academic part of the class. Then there's the diving. I use the first dive to show my students how to properly plan and execute a deep dive, including making a free ascent using an SMB and spool. The rest of the class is them planning and executing dives to show me that they understood what we have done up to this point. It is only at this final stage that I am evaluating them. Up to that point, I'm teaching ... which is what they've paid me to do.

... Bob (Grateful Diver)

 

[MXGratefulDiver]

So finding out that you could not teach them does not make them a bad student! Difficult to teach does not equal bad! (Do not read into this as me saying you are a bad teacher.) You just did not peak the "bad students'" own interests with the way you put the info out there. I do not care which agency policy is followed!

I still say there are no bad students! Everyone can attain an education, or learn all
skills needed to dive safe. You just have to figure how to pass on the info

That being said, Instructors have the info, if you can't get someone to be interested in your class you are right to turn them away or as you said reset the expectations.

See you topside! John

I agree with everything you just said ... to a point.

It is extremely important for people to find an instructor whose teaching style matches their learning style.

A mismatch, however, is not what makes someone a bad student.

Deciding to sign up for a class and then refusing to put the required effort into learning the class objectives is what makes someone a bad student. There are ... believe it or not ... people out there who feel that they are paying for a C-card ... rather than the opportunity to earn one. For those people, no instructor will make them a better student. They will only, eventually, succeed in finding an instructor who will sell them what they want to buy.

... Bob (Grateful Diver)

 

[jbtut]

Shouldn't an OW diver know all of that already?

 

[MXGratefulDiver]

Shouldn't an OW diver know all of that already?

OW divers are introduced to a diverse range of topics ... many of which they will gain no actual experience in during the class. These topics may or may not mean anything to them, other than as an intellectual exercise.

As you continue through the educational process, you will come back to a lot of these topics, examining them in greater detail, and learning both how they apply to your dives and why it's important to understand at a more detailed level.

This process never really ends. To say, for example, that someone understands decompression sickness in OW means only that they have read about the root causes and general symptoms. As your knowledge of decompression increases you will learn more about what breathing pressurized gas does to your physiology, strategies for managing the offgassing process, and why (as an example) different dive computers will give you such wildly variable results for the exact same dive profile.

As you continue the learning process, you will slowly come to understand the tremendous number of variables involved in decompression, and why ... as your expertise increases ... you reach a point where there are more questions than answers.

A famous analogy from an IANTD article on the subject goes something like this ...

If you ask a random, non-diving person on the street to explain what's really going on inside a diver's body that leads to decompression sickness, the answer is likely to be "I don't know".

If you ask the same question of a typical scuba diving instructor, the answer will likely be that nitrogen is absorbed by body under pressure (a result of Henry's Law); and that if a diver ascends too quickly, the excess dissolved nitrogen in the blood will "come out of solution" in the blood to form tiny bubbles; and that these bubbles will block blood flow to certain tissues, wreaking all sorts of havoc.

Pose the question to an experienced hyperbaric medical expert, and you will probably get an explanation of how "microbubbles" already exist in our blood before we even go underwater; and that ratios of gas partial pressures within these bubbles compared with dissolved partial pressures in the surrounding blood (in conjunction with a wide variety of other factors) determine whether or not these microbubbles will grow and by how much they will grow; and that if they grow large enough, they may damage the walls of blood vessels, which in turn invokes a complex cascade of biochemical processes called the "complement system" that leads to blood clotting around the bubbles and at sites of damaged blood vessels; and that this clotting will block blood flow to certain tissues, wreaking all sorts of havoc. You will likely be further lectured that decompression sickness is an unpredictable phenomenon; and that a "perfect model" for calculating decompression schedules will never exist; and that the best way to calculate the best decompression schedules is by examining probabilistic patterns generated from reams of diving statistics.

If, however, you seek out the world's most learned scholars on the subject of decompression and decompression sickness, the top 5 or 6 most knowledgeable and experienced individuals on the subject, the ones who really know what they are talking about; the answer to the question of what causes decompression sickness will invariably be: "I don't know". As it turns out, the random non-diving person on the street apparently had the best answer all along.

It's a good article, by the way ... and very appropos to the diver who is considering deep diving ... http://www.iantd.com/rebreather/phys.html

All of the subjects you learned in OW were really only surface scratches ... below those scratches lies a deep mine filled with veins of valuable knowledge. As you continue diving ... to whatever level you decide to take it ... you will never stop mining those veins. Among the things you will come to realize is that nobody really knows it all ... and probably never will ...

... Bob (Grateful Diver)

 

[stargost]

To op/divor,

Padi material should just be taken as introduction, and as reasonable adults, it is always good to look for more.
in addition to the useless deep dive padi book, you can get "deco for diver" from M. Powell
Amazon.com: Deco for Divers: Decompression Theory and Physiology (9781905492077): Mark Powell: Books


I believe this course maybe for rec. divers who want to go little beyond the 60ft without going to advance (not sure I understand why, but why not) or for divers who only did the AOW 100ft dive once and would like to be coached to do more or do beyond the limit of 100ft in case they would like to see a special locations.
Maybe not needed, maybe the course is basic compared to the AOW book, but it will provide little more advices anyway.

But for really deep, has to think CMAS3 which gets you to 180ft on air, and then indeed, the Padi book maybe too little ;-)

 

[oddible]

Regardless of the value of a good instructor, the material for a class should typically exceed the needs of students or at least offer resources where students can develop their own personal knowledge (sure you can get this from an instructor but the curriculum should be developed to that point anyway). Did you take the class for the cert or for the knowledge? If you took it for the cert then you got exactly what you paid for. If you took it for the knowledge you got ripped off.

So in clarification - if a OW diver takes the AOW course does that certify them for deep diving? Will dive ops take an AOW to depths beyond 18m (60ft) with an AOW card? And do you get a greater depth of knowledge regarding deep diving from AOW than from the deep specialty?