How you ID your Deco tanks

[Michael Guerrero]

Most of my diving I have done is training diving, not as much as rec diving, because I fill I don't learn a Fuc...thing by just diving recreational, and I differ with more you dive better you get, you get more confident that is all, it doesn't mean you are getting better, if I don't push my self to do something different then I don't learn.

Maybe this is your problem. My view is you should be doing the bulk of your learning and skill development in your personal diving, not in a class. The class is there to introduce you to techniques, theory, planning considerations, and beat you down a little in terms of challenging you with task loading so that you understand these things take time to master.

If you're not practicing these techniques outside of the training environment, you're doing it wrong. If you're going from class to class without cementing the skills and truly understanding the theory and principles you learned in the previous one, you're doing it wrong. The only way to master the things you learn is by diving, practicing, and thinking.

I don't have much opportunity for tech diving where I currently live, but I can still go to a nearby place and spend an hour or two at 80ft practicing my skills. I can shoot bags, wear, swim with, and manipulate bottles, do actual deco dives if I stay down long enough, practice various failures (reg, inflation, drysuit, light, etc.), work on not silting up the bottom, etc. I don't even need a buddy for any of these. I can run through the scenarios in my head about combination failures, practice a mock deco schedule after a mask failure, ensure that what I think my backup equipment/procedures are actually work and that I'm capable of executing them successfully (e.g., lift bag as backup inflation).

Outside of the water I can watch tons of videos on the proper technique, evaluate my technique from video I've shot of myself in the water, read up on and/or watch presentations on decompression theory, equipment configuration, and planning considerations/techniques. I can learn how my equipment works from books and for the more adventurous (though some of it really is trivial) by taking things apart. Learn about human physiology so that I can critically evaluate the information my agency and instructor provide me (because they can just be plain wrong or unsupported by evidence). I can learn about how gas is blended, tanks and equipment are cleaned and serviced, and when someone is full of BS.

In my view, (technical) divers have a personal responsibility for their own development, knowledge, and skill. The instructor is there to guide you on your journey. It is your responsibility to make yourself a skillful, competent, and capable diver. Your instructor can help you learn techniques and avoid pitfalls that would be costly or fatal for you to learn on your own.

 

[DevonDiver]

The class is there to introduce you to techniques, theory, planning considerations, and beat you down a little in terms of challenging you with task loading so that you understand these things take time to master.

I guess this depends on teaching style of the instructor and the learning style /motivation of the student.

The real job of the instructor is to provide what the student can't do for themselves:

1. Demonstrate and display optimal role-modelling attitude, skills, protocols and procedures for the student to see and learn.

2. Observe and correct student performance, to firstly permit acquisition and later allow application under increasingly elevated levels of demand.

3. To assess student performance and give detailed remedial feedback on that. This both aids skill /protocol refinement and also provides the student with an overall benchmark of the competency (see earlier post on psychological issues with assessing your own competency).

The instructor is there to make the diver better. Many (but a reducing number sadly) divers prepare themselves for technical training through theory research and fundamental skills practice.

If the instructor were only to "introduce" things, then they'd be potentially under-teaching. The instructor should raise the student as high as training duration allows.

Obviously, there's a benchmark competency that defines certification level, interpreted by the agencies' and instructor's standards, and the instructor has to provide assessment to ensure that the student meets or... ideally... exceeds that.

If you're not practicing these techniques outside of the training environment, you're doing it wrong. If you're going from class to class without cementing the skills and truly understanding the theory and principles you learned in the previous one, you're doing it wrong. The only way to master the things you learn is by diving, practicing, and thinking.

Understood and agreed. I'd merely point out a difference between doing 'diving' and doing 'dedicated practice'.

Simplistically stacking up the numbers in your dive log isn't an efficient way to develop skills and ability. You need to commit to dedicated, focused practice work...with feedback... to see tangible results per session.

Feedback and corrective steps is what the diver needs help with. An instructor... or if available, a mentor with expertise... is invaluable for this.

As the quote goes: "Practice doesn't make perfect. Only perfect practice makes perfect".

It's the instructor who ensures the diver is doing 'perfect practice'. The student is ready to continue alone only once they have perfect skills to practice.

As an example:

I had a technical student for 3 weeks of training in Oct/Nov. We completed over 40 hours in-water... averaging 2-3 hours a day. Few people can sustain more than that when doing intensive, focused practice. Most of that training was shallow skills work.

Only when skills were cemented did we seek to apply them on assessed dives. The assessed dives highlighted new areas for practice that formed the basis of further shallow training. For instance, when he struggled to shoot a DSMB on an application dive, our next step was to spend a focused hour practicing only DSMB deployment, using a spectrum of drills - until he could do it reliably in under 40 seconds, without any degredation to his fundamentals and situational awareness.

The development was staggering... and the diver (who first arrived with only 44 logged dives) finished training with a very high level of skill...and a low level of stress in check-out dives. The training delivered in reasonably 'finished product' in a very short timescale.

The next student, a qualified dive instructor with hundreds of dives, was much more limited in available training time. We had only 5 days for training...reflecting 'only' ~10 hours in-water. Whilst that student did achieve the necessary standard for certification, there was clearly still vast requirement for further practice time... and this was illustrated by the persisting level of stress and task loading on his checkout dives. The training ensured basic safe competency at entry-level tech, but wasn't a 'finished product'... the student had a 'route map' for future development. But that development will demand hundreds of hours of self-guided practice and problem-solving to identify and remedy performance deficits.

For the same reasons, this is why programmes like the GUE Fundamentals achieve effective results. They set a standard to be achieved and commit significant in-water training time to dedicated skills/protocol practice. The feedback given in-water and post-dive is critical to timely and effective improvement.

In short...what gets efficient results is hours of hard work doing unglamorous diving, with detailed and timely performance assessment against stringent standards.

This provides the baseline ability from which you go out and do dives to apply those skills and gain experience.

Too many divers focus on trying to apply skills that aren't yet a reliable baseline. Running before they can walk.

In my view, (technical) divers have a personal responsibility for their own development, knowledge, and skill. The instructor is there to guide you on your journey. It is your responsibility to make yourself a skillful, competent, and capable diver. Your instructor can help you learn techniques and avoid pitfalls that would be costly or fatal for you to learn on your own.

I concur. The article I wrote (linked in earlier post) describes the concept of taking 10,000 of dedicated practice to reach a level of expertise.

The instructor is the pre-cursor to that practice. They must teach skills and protocols 'perfectly' so that the student can continue to ingrain them 'perfectly' thereafter. They must shape the correct mindset. They must teach theory appropriate to the diver's needs (typically well expanded beyond the contents of a textbook)... and they must have the expertise to effectively critique and resolve student performance deficiencies (be a great teacher and coach).

Most importantly, the tech instructor must ensure that the student has a baseline competence, safety and correct mindset, before issuing certification that exposes the student to diving at levels where there is significant risk, high physical and psychological demand... and is typically very unforgiving of single errors.

Mindset is critical because tech divers who are content to 'learn from their mistakes' on actual dives probably shouldn't expect a long lifespan.

 

[Remy B.]

Will noted Micheal

In Nederland if you want to go to 80ft and not have the problems with boat traffic overhead you need to go to lakes, which are, Dark and cold, I will not put my self in that position doing the drills in that conditions alone, those conditions are actually excellent because they are hard, no reference, and cold, but I find that as to risky to do by my self.

And like Andy mention, you can't have another critic opinion how you are actually executing the scenarios and drills, for me having that other person to critic me is very important.

It is kind of what I see in my work environment, I constantly see and hear people saying about I have 25 years experience, bla,bla,bla, but they have been doing it wrong for all that time, because they have actually not taken the time to go to a course and update them self with the right information, and they don't have another critic perspective of what they are not doing good enough

The biggest problem for me is that I don't have a buddy to go to the drills and scenarios, that I find to be the most valuable way to get better in diving after the tools and knowledge giving in a tec course, unfortunately I have not had the luck to find one.

 

[stuartv]

I guess what I am trying to say is wouldn't you deal with all the stuff that has stacked up on you, and then do your gas switch. Why add an additional task that isn't an immediate necessity if you are already task loaded. At my level, I am only doing 1 deco gas and I can breath my back gas at any point in the dive. If I have anything going on, I am not doing my gas switch until I have resolved the issue and am back to a stable platform. That may change once I move deeper into the tech realm, dealing with multiple deco bottles, or hypoxic backgas, but by that point, my skill set should be as such that I would be less task loaded by the other things.

I'll out myself with an example from my own experience.

Start with diving dry. Then do a dive with some slightly (innocuously, seemingly) different dive parameters that result in a small miscalculation of weighting that results in being just a little light. Not light on the first dive. Light on the second dive on the same set of doubles. You do the whole dive never feeling light at depth (>110' the whole time). You build up a few minutes of deco obligation before you start your ascent.

You get to 30' and it's time to switch to your bottle of 80%. But, now you're so light that you're having trouble staying down. Your suit doesn't seem like it's dumping gas quickly enough so you twist the exhaust valve all the way open - except that you were being a dumbass and twist it closed, not open.

So, now you are hanging on the anchor line, upside down with your drysuit feet full of air, in limited viz. Oh, and your mask that has been letting in a trickle of water through the whole dive is still leaking but now it's really hard to clear, and the water in your mask (while you're upside down) is making it nigh on impossible to actually read your computer. And it's time for a gas switch.

Even though it's just one bottle to deal with and switch to, it can be pretty stressful.

 

[PfcAJ]

I'll out myself with an example from my own experience.

Start with diving dry. Then do a dive with some slightly (innocuously, seemingly) different dive parameters that result in a small miscalculation of weighting that results in being just a little light. Not light on the first dive. Light on the second dive on the same set of doubles. You do the whole dive never feeling light at depth (>110' the whole time). You build up a few minutes of deco obligation before you start your ascent.

You get to 30' and it's time to switch to your bottle of 80%. But, now you're so light that you're having trouble staying down. Your suit doesn't seem like it's dumping gas quickly enough so you twist the exhaust valve all the way open - except that you were being a dumbass and twist it closed, not open.

So, now you are hanging on the anchor line, upside down with your drysuit feet full of air, in limited viz. Oh, and your mask that has been letting in a trickle of water through the whole dive is still leaking but now it's really hard to clear, and the water in your mask (while you're upside down) is making it nigh on impossible to actually read your computer. And it's time for a gas switch.

Even though it's just one bottle to deal with and switch to, it can be pretty stressful.

You are not in a position at that point to switch gas.

Sort out your business first, then (and only then) is it gas switch time.

 

[stuartv]

You are not in a position at that point to switch gas.

Sort out your business first, then (and only then) is it gas switch time.

What do you sort out? You're too light. Your mask is leaking. In your mind, your exhaust valve is all the way open.

I held onto the anchor line with one hand, did my gas switch with the other, and finned myself (hard) down to horizontal so I could clear my mask enough to read my computer, so I could know when my deco was clear. Then got out and noted my lessons to be learned. And thanked my lucky stars it wasn't a drift dive and I had an anchor line to hold onto.

My post was not a solicitation of a critique. It was to give an example where "getting stable" before a gas switch isn't always that easy. Admittedly, it was the result of a compilation of small errors on my part. But, if you dive with a presumption that you won't make mistakes, then, well, you dive differently than I do. I do my best to not make mistakes, AND to plan contingencies for making them nonetheless.

 

[PfcAJ]

What do you sort out? You're too light. Your mask is leaking. In your mind, your exhaust valve is all the way open.

I held onto the anchor line with one hand, did my gas switch with the other, and finned myself (hard) down to horizontal so I could clear my mask enough to read my computer, so I could know when my deco was clear. Then got out and noted my lessons to be learned. And thanked my lucky stars it wasn't a drift dive and I had an anchor line to hold onto.

My post was not a solicitation of a critique. It was to give an example where "getting stable" before a gas switch isn't always that easy. Admittedly, it was the result of a compilation of small errors on my part. But, if you dive with a presumption that you won't make mistakes, then, well, you dive differently than I do. I do my best to not make mistakes, AND to plan contingencies for making them nonetheless.

I'd say that if I was in your situation, getting the air out of my feet would be a priority action. Obvi if there's air in my feetsies and I flip a 180 (head up now) that gas is still somewhere if it didn't go out of my exhaust valve.

Once that's solved and I'm stable in the water column (apparently the upline is solid enough to hold on to in this wacky scenario) I'd fiddle with my mask. Can't switch if I don't know what depth I'm at. Maybe then it's time to gas switch once I can see.

It's decidedly not time to switch when upside down white-knuckling an ascent line with my mask full of water.

 

[Jack Hammer]

Switching to your deco gas then swimming down deeper is not a good idea. Better to sort out the problems then switch gas and begin deco later than to exert yourself on a high PPO2. Its importent in Tech diving to understand how to prioritize the many things you may encounter. (@stuartv , not meant as criticism, you're relatively new to the game)

 

[stuartv]

Switching to your deco gas then swimming down deeper is not a good idea. Better to sort out the problems then switch gas and begin deco later than to exert yourself on a high PPO2. Its importent in Tech diving to understand how to prioritize the many things you may encounter. (@stuartv , not meant as criticism, you're relatively new to the game)

I didn't mean swim deeper. I meant hold onto the anchor line to maintain my depth but fin my body down to be horizontal and level with my hands. When you're so light that you have to hold on to keep from floating up, it's the only way to get horizontal.

 

[rivers]

I'll out myself with an example from my own experience.

Start with diving dry. Then do a dive with some slightly (innocuously, seemingly) different dive parameters that result in a small miscalculation of weighting that results in being just a little light. Not light on the first dive. Light on the second dive on the same set of doubles. You do the whole dive never feeling light at depth (>110' the whole time). You build up a few minutes of deco obligation before you start your ascent.

You get to 30' and it's time to switch to your bottle of 80%. But, now you're so light that you're having trouble staying down. Your suit doesn't seem like it's dumping gas quickly enough so you twist the exhaust valve all the way open - except that you were being a dumbass and twist it closed, not open.

So, now you are hanging on the anchor line, upside down with your drysuit feet full of air, in limited viz. Oh, and your mask that has been letting in a trickle of water through the whole dive is still leaking but now it's really hard to clear, and the water in your mask (while you're upside down) is making it nigh on impossible to actually read your computer. And it's time for a gas switch.

Even though it's just one bottle to deal with and switch to, it can be pretty stressful.

I would say you needed to spend time sorting out your weighting in a drysuit and twins in the shallows before attempting a deco dive. You were trying to run before you could walk.