Decompression and the recreational diver

[Bob DBF]

One situation supposes the ability to; carry enough gas, control your buoyancy and follow what your computer tells you to do.
QUOTE]

Try it without a computer or SPG, somtimes using a horse collar on twin 72's with a J valve (or not). People used to make dive plans before Tech Diving which, I believe, made it's debut in 1991.

To lower my blood pressure I began reading posts more literally, unless it is written "formal training" I assume that the poster means any training methods that will bring you to the desired end under discussion.

As Captain has written those manuals have held up well over time and any truly new literature on specific types diving, advances in dive medicine, and training methods can be bought by anyone, read and understood. The concept that all knowledge has to be spoon fed to students is relativly new and has been brought about by the same "formal training" that has been lowering the OW diver standards.

The drumbeat for formal training, classes and cards or your gonna die seems to be from those who's ricebowl will be filled. Not saying formal training or instructors do not have their place, but they have a dog in the fight.


Bob
-------------------------------
I may be old, but I’m not dead yet.

 

[Dave1981]

The facts do not support your assertion. A vast number of complex decompression dives have been successfully completed by people with no more training than a good recreational Scuba course, reading a book or manual, talking to friends, gradually developing skills, and reflecting on their experience. After all, this is how the skills you teach were developed.

That's reckless at best. How many died or spent time in the chamber in order to get us to the level we are now? These guys lived and breathed diving, pushed the limits to find where things went and on occasion paid the price for it. They didn't do a 3 day course then start to follow a computer beyond the limits to see what happened.

It's downright stupid to do so without knowing the little things. Sometimes things that seem second nature to a diver of one level are not even a consideration for someone that doesn't know those things, the difference between an instructor and proper course vs. an experienced diver mentor is that the instructor has the requirement to impart knowledge that may seem second nature to an experienced diver.

With all the best intentions in the world an experienced mentor can easily assume you already know what they consider to be basic level knowledge and unknowingly put you at considerable risk. With the current accessibility of courses to teach you what you don't know, that approach is not an acceptable one. I would also propose that anyone willing to take you beyond your level is not quite the experienced mentor you think they are.

Dave

 

[Thalassamania]

That's reckless at best. How many died or spent time in the chamber in order to get us to the level we are now? These guys lived and breathed diving, pushed the limits to find where things went and on occasion paid the price for it. They didn't do a 3 day course then start to follow a computer beyond the limits to see what happened.

A lot of goats, remarkably few people, spent time in a research chamber in order to get us to the level that we are now. Others who damaged themselves spent time in treatment chambers, but that did not do much to get us to the level we are now.

It's downright stupid to do so without knowing the little things. Sometimes things that seem second nature to a diver of one level are not even a consideration for someone that doesn't know those things, the difference between an instructor and proper course vs. an experienced diver mentor is that the instructor has the requirement to impart knowledge that may seem second nature to an experienced diver.

Naw, the difference is that the mentor has actually done the dives, the instructor has been taught to teach about doing the dives, but the best of all possible worlds, a mentor who got agency holy water sprinkled on him once upon a time is also a possibility.

With all the best intentions in the world an experienced mentor can easily assume you already know what they consider to be basic level knowledge and unknowingly put you at considerable risk. With the current accessibility of courses to teach you what you don't know, that approach is not an acceptable one. I would also propose that anyone willing to take you beyond your level is not quite the experienced mentor you think they are.

Dave

Dave, that is some of the worst clap-trap that I have ever read. The average instructor today has a breath and depth of skill and knowledge that doesn't match that of a whole lot of open water divers that have gone through quality programs, but since you've only been diving for four years or so, I can't hold your opinion against you; there's a good change that you've never seen the sort of student I'm talking about. I'd prefer (and have always preferred) a mentor, in fact, I can't think of a single course that I ever took save CPR kind of stuff that was ever on any other sort of basis.

 

[Akimbo]

That's reckless at best. How many died or spent time in the chamber in order to get us to the level we are now? These guys lived and breathed diving, pushed the limits to find where things went and on occasion paid the price for it. They didn't do a 3 day course then start to follow a computer beyond the limits to see what happened…

I’m not sure exactly what guys you are talking about. As far as having to spend time in a chamber you must be talking about the diving pioneers of the 1800s and early 1900s, long before Cousteau met Émile Gagnan. Early tech divers that experienced decompression and barotrauma injuries made those errors due entirely due to their own lack of investigation and operational preparation.

As you know, good numbers are hard to come by. If you are talking about east coast wreck divers in the late 1980s and early 90s, from what I have read the rate is not much different than today. They re-learned a few hard lessons, but mostly ignored what was already widely known. They averaged better physical condition and experience than today. These factors plus rebreather related incidents further fog the comparison to now.

If you are talking about deep air divers in the 1960s there isn’t much data to say but my sense from the magazines of the day is there was almost no concern over deep decompression diving. The editorials were mainly about sounding the alarm over the on-slot of marginally trained resort/vacation divers in shallow water. Cave diving has probably shown the most improvement and innovation, but it had more to do with managing lines. A lot of information on gas management seems to have been rediscovered but I haven’t seen anything fundamental.

I hope you are not thinking that mixed gasses, gas switching, or the use of oxygen as innovative. There was a lot of refinement through the 1970s, but it was virtually all based on published work from EDU in the 1930s. Considering that early tech divers’ main focus was using Helium on the cheap, they didn’t do a bad job at all.

There has been a slow and incremental improvement in decompression algorithms and especially computers to run them, but nothing dramatically more complex operationally than was in the US Navy Diving Manuals from the 1950s.

Even the rebreather refinements are primarily centered on improvements in electronics, but are fundamentally based on slow incremental improvements of the ElectroLung and GE Mark 10 from the late 1960s and early 70s.

… It's downright stupid to do so without knowing the little things. Sometimes things that seem second nature to a diver of one level are not even a consideration for someone that doesn't know those things, the difference between an instructor and proper course vs. an experienced diver mentor is that the instructor has the requirement to impart knowledge that may seem second nature to an experienced diver….

You are singing from my page here. Unless you misread my intent and missed my other writings, I am one of the biggest proponents of much longer basic Scuba training that provides a sufficient foundation to understand decompression dives with as much gas as a diver can carry. Beyond that I am also a proponent of slowly and progressively gaining experience and evolving deeper as personal objectives dictate.

Unfortunately very few of the little things that actually keep divers from killing themselves in adverse situations can be made intuitive and reflexive even in diving classes. From personal experience, that includes ones that run for cumulatively seven months and 40 hours a week. That develops from a deep understanding that only comes with time, experience, and reflection. Please don’t confuse comparing the reality of what ill-trained divers can and do perform and advocating for it. I believe my full comments you quoted partially made that clear.

 

[redacted]

You can't do the decompression stop without the gas,
And you won't have the gas unless you planned for it,
And you can't plan for it without the knowledge,
And you won't have the knowledge without the training,
And you won't get the training in a recreational course.

There are many ways to acquire knowledge without training. A recreational course in "light deco" might make it easier to obtain knowledge but it is far from essential.

 

[davetowz]

IMHO... as one who is (self determined) a rather skilled Rec diver who is on the trail into the "tec" realm. The issue is not the science behind performing the obligatory stops as a table or software or maybe a puter tell you to do it, but it is the development of skills and comfort in the water that will allow you to deal with any issue that may arise without first thinking... the surface is safety. Can a diver develop that alone...of course... can those skills be assisted by a good mentor, yep. But in the end the way most of us will get the lesson beat into us that we have a shortcoming within our skillset is an honest instructor saying...you suck at that...let's work on this.
Last time I looked...that was not available in a book or online. Have many done this stuff without the assistance of an instructor..hell yes, that is where the original knowledge base that helped create the tech programs came from.

 

[Thalassamania]

Unfortunately a whole lot of the information has not been passed, and what has been was driven more by ego or pecuniary interests (oft both) rather than a desire to advance the state of practice. This lead to lilliputian style flame wars that still go on and continue to shed way more heat than they do light.

 

[DevonDiver]

Perhaps nothing in YOUR comes close to providing that level of training, that focus or that mindset, but you have no business speaking for everyone else.

I base my overall perceptions on the people I see as customers. The breakdown of those customers' training sources probably reflects the overall market spread. The majority are PADI. SSI comes second. CMAS/NAUI/YMCA/BSAC very occasionally. A few GUE/UTD divers.

I haven't dived with anyone trianed under your system Thal - but that's something I would be genuinely interested to do.

"Safe when broken" is a "safety stop" not a decompression stop. I don't know the exact difference between "light" deco and deco,

I share that opinion. If my dive planning tells me that during the dive there will be a situation where I cannot access the surface within a timescale that I can survive without respiration, then I have to plan and prepare for every reasonable contingency to ensure my survival.

Those contingencies include, but are not limited to; staying longer than I planned at depth, going deeper than I planned, regulator failure, BCD failure, gauge/computer failure and other equipment failures. In addition, my contingency planning has to assume that more than one of these issues can occur simultaneously.

Planning and preparing for those contingencies involves a level of 'technicality' beyond the formal training provided in mainstream recreational diving syllabus.

Ok... I don't want to get 'hung up' with vocabulary. But.. I don't think it's unfair to apply a 'name' to a level of diving activity that demands a high level of technicality; precision and the use of specific techniques. Such distinctions are readily available throughout life:

Drawing:

1. A picture or diagram made with a pencil, pen, or crayon rather than paint, esp. one drawn in monochrome.
2. The art or skill or making such pictures or diagrams.

Technical Drawing:
1. The practice or skill of delineating objects in a precise way using certain techniques of draftsmanship, as employed in architecture or engineering

It sounds like a lot of makeup work that the student should have mastered previously, but didn't, so you had to provide it. Good thing you could and were willing to, but you really should be complaining about this student's previous teacher(s) rather than bragging on what a hard program you present.

Firstly, most 'recreational' scuba divers are taught upon the premise that direct ascent to the surface will always be an option available to them. That premise impacts upon the scope and nature of the contingency planning and emergency drills that they are taught. I don't understand why that student should have been taught specific and precise techniques for diving in situations where the surface isn't an immediate option.

Secondly, I am neither complaining about the student's former teacher, nor "bragging" about the program I present. My intentions were to demonstrate how cheap, convenient and, well...easy... my 'technical' training course was. Within a matter of 3 days, the student will receive the information and skills they need to safely complete 'light' deco dives. I was trying to dispel any accusations that doing a 'tech' course for light deco was a waste of money, or a rip-off. For the sake of $135 a day, over 3 days, the student is saved having to read dozens of books and spend hours online in research...and conduct (and pay for) dozens of dives to progressively develop and experiment with skills. They get an in-depth performance critique and feedback. They get my undivided attention and all the diving logistics are prepared for them - because it's a paid service, not a 'favour'. They'll also get a plastic card and their name and certification listed on a verifiable online database.

Assuming that I'll work a minimum of a 10 hour day, 8am to 6pm (it truth, I'll be doing evening theory sessions also)... that works out at $13.50 an hour, including dives and manuals. Some people pay more than that just to have their lawn mowed, or dog groomed. How much do people pay for driving lessons nowadays? $60-$90 an hour?

The major problem that most students I have trained have with longish stops is dealing with boredom not with skill performance.

Me too. That's why I have mentioned 'mindset'.. and the development of focus and self-discipline... plus the education of risks/consequences.

Again, in most mainstream 'recreational' diving courses there is little or no emphasis on those factors. The mindset is different.

(please note: I am not being 'absolute' about this...'most' and 'mainstream' are caveats I shall try to include henceforth).

Once again I must point out that safety means "without risk."

And yet, nothing is without risk. The word 'reasonable' should be included.

How about this: Appropriate training should maintain a uniform level of risk, regardless of activity.

A technical diver should be 'as safe' as a recreational diver. As exposure to potential danger increases, skill, knowledge and preparation should be expanded to mitigate those dangers. Training is available to provide specific and precise techniques to mitigate foreseeable and reasonable risks. The diver should conduct their activities in such a way as to ensure a reasonable level of safety.

With regards training, it's useful to consider the difference between 'negligence' and 'reasonable prudence'. In a court of law, would someone be determined 'negligent' or 'reasonably prudent' in the way they sought to prepare for and conduct a dive? Would it 'reasonably prudent' to undertake further formal training prior to engaging in an activity with elevated and novel risks, that are beyond the scope of previous training?
Would doing decompression, without any contingency planning, redundancy or other risk-specific preparations be considered 'negligent'?

There is no decompression diving that is without increased risk so the very idea of being able to 'safely carry out decompression dives' is claptrap. What one must do is learn to minimize risk whilst carrying out a decompression schedule. That is a very different mind set.

I agree. That is what I attempted to communicate before. I obviously communicated it badly, my apologies.

Any properly trained open water diver should have the ability to; carry enough gas, control your buoyancy and follow what your computer tells you to do.

Yes, they should. Does that alone constitute 'reasonable prudence' to minimize risk whilst carrying out a decompression schedule?

What if their gas supply failed? What if a regulator failed? What if their BCD failed? What if their computer failed? What if they are forced to over-stay on the bottom? What if they are forced to go deeper? What if several of these issues occurred simultaneously...?

Is a properly trained open water diver expected to deal with those... whilst remaining on a precise stop depth and/or maintaining a pre-determined ascent?

Training is not needed to do decompression dives, I did hundreds before I was mentored by someone who had done far fewer, but who had some good tricks. I guess it would be safe to say that I still have yet to be so "trained."

To lower my blood pressure I began reading posts more literally, unless it is written "formal training" I assume that the poster means any training methods that will bring you to the desired end under discussion.

Bob has a good point. In the future, I will certainly endeavour to indicate "formal training" where I literally mean it.

I've always championed the need for specific training for decompression diving. I believe that training should be appropriate to activity and risk.

My development as a diver has consisted of both training and 'formal training'. Probably more of the former, than the later. The limits of my training certainly far exceeds the limits of my 'formal training'.

I think that 'formal training' is an efficient, timely and cost-effective method of receiving training. I do not think it is the only method of training.

Formal training (certification) is also the most effective manner of ensuring that your training is recognised. Training recognition can be a very important factor when you might rely on external/private resources or services to conduct your dives.

Formal training also tends to reduce risks as the student is developing - if for no other reason than the instructor is conscious of legal repercussions of providing a duty of care to that student. A diving mentor or internet advisor is not necessarily under that obligation.

Formal training also tends to include some form of review, assessment or appraisal of the divers proficiency relative to the diving undertaken. I feel that this is invaluable. Again, that's not necessarily the case outside of formal training courses.

 

[davetowz]

Bob has a good point. In the future, I will certainly endeavour to indicate "formal training" where I literally mean it.

I've always championed the need for specific training for decompression diving. I believe that training should be appropriate to activity and risk.

My development as a diver has consisted of both training and 'formal training'. Probably more of the former, than the later. The limits of my training certainly far exceeds the limits of my 'formal training'.

I think that 'formal training' is an efficient, timely and cost-effective method of receiving training. I do not think it is the only method of training.

Formal training (certification) is also the most effective manner of ensuring that your training is recognised. Training recognition can be a very important factor when you might rely on external/private resources or services to conduct your dives.

Formal training also tends to reduce risks as the student is developing - if for no other reason than the instructor is conscious of legal repercussions of providing a duty of care to that student. A diving mentor or internet advisor is not necessarily under that obligation.

Formal training also tends to include some form of review, assessment or appraisal of the divers proficiency relative to the diving undertaken. I feel that this is invaluable. Again, that's not necessarily the case outside of formal training courses.

And how. Best part of the whole thread, so far.

 

[Rhone Man]

What does it really matter what certifying agencies say? The premise of this conversation is lots of people ignore their recommendations anyway. Those that don’t do so by personal choice. The reality is that the individual is the only person that can determine what is acceptable to them. We can wring our hands all day and nothing will change. Unfortunate but ultimately true, Darwin is the final arbitrator.

I think the reason that it matters is awareness. Before I did my first tec diving course, I assumed decompression procedures was about learning how to hang on a line. It was a bit of a revelation that it wasn't really about learning about the stops, or even cutting the tables - most of it was about planning the gas.

I am guessing that many (most?) of the people who do engage in regular "light deco" diving similarly do not think a lot of about their gas planning, and I am sure there are those who don't even think about gas redundancy. Courses which bring a greater level of awareness (such as solo diving courses, and a putative "light deco" course) would do more to raise awareness and bolster relevant skills than many of the intermediate courses now available.