Decompression Course

[KenGordon]

The "line" is more real than you're giving it credit for, I think. Unless you believe decompression to be just as optional as a safety stop or feel that you're somehow more physiologically tolerant than the decompression model, on the other side of that line you put yourself at a greatly increased risk of injury.

Nobody is saying that deco obligations can be ignored, quite the opposite, CMAS and BSAC are absolutely about safe diving (here are 57 pages of the rules http://www.bsac.com/sdp/) however part of that involves dealing with the reality of independent people going diving. Thus they are trained for the start to do deco dives. Then it is up to the diver to decide what equipment is appropriate for the dives they do. The training (BSAC at least) includes how to figure that out.

In the BSAC system the local club members are directly responsible for their own safety, and the DivIng Officer is responsible that the club dives conform to the Safe Diving Practices. Thus peer pressure encourages doing the right thing.

If serious, regular divers trained by "mainstream" agencies are diving to rules designed to protect warm water, once every few years divers for hurting themselves then that is ok I suppose but there is a place between that and full blown cave or wreck penetration at depth with multiple deco gases and an hour of deco.

 

[rivers]

Nobody is saying that deco obligations can be ignored, quite the opposite, CMAS and BSAC are absolutely about safe diving (here are 57 pages of the rules http://www.bsac.com/sdp/) however part of that involves dealing with the reality of independent people going diving. Thus they are trained for the start to do deco dives. Then it is up to the diver to decide what equipment is appropriate for the dives they do. The training (BSAC at least) includes how to figure that out.

In the BSAC system the local club members are directly responsible for their own safety, and the DivIng Officer is responsible that the club dives conform to the Safe Diving Practices. Thus peer pressure encourages doing the right thing.

If serious, regular divers trained by "mainstream" agencies are diving to rules designed to protect warm water, once every few years divers for hurting themselves then that is ok I suppose but there is a place between that and full blown cave or wreck penetration at depth with multiple deco gases and an hour of deco.

I wouldn't say BSAC is any more or less safe than any other agency out there. BSAC, at a national level, they do a lot of things that don't make sense (hog loop debacle anyone?). But luckily, at club level, especially if you're in a good club, some of those things don't matter. I have also seen some absolutely atrocious clubs that shouldn't be diving, let alone training people. One of BSAC's biggest weaknesses, is the lack of quality control, but you also get that with some of the PADI, SSI, and some of the other agency instructors as well. It can even vary between instructors in club.

 

[NL1983]

One thing I do know is that I have never had any trouble with CMAS and BSAC divers who dived with me, and that cannot be said for PADI divers ... Again I don't know all there is to know about their systems, but it sure seems to work.

The PADI system is simply popular because it is a 'fun-and-easy-we-are-on-holiday-and-want-to-dive-system' for at least all courses up-to rescue / dive-master. It depends more on the individual how much proper knowledge they gain during training than on the method of teaching. Clearly the instructor plays a role in bringing the right knowledge across and ensuring people understand too, but the actual knowledge testing and practical testing is relatively limited and people can pass that without fully grasping the insights. Additionally average PADI divers seem to do a couple of dives a year (at least the ones that come to Indonesia to dive) vs. it seems that CMAS and BSAC divers are more of the "every-weekend" type of divers.

Although not taught in the PADI recreational system, I don't fully understand the fixation about the NDL. I understand that if you are on a single tank you don't want to build up massive amounts of deco and go to great depths requiring several deep-stops etc etc, but why is that line so "holy"? When I dive in places like Ambon or Lembeh (with my girl-friend as a buddy, and without students and/or people to supervise) I do get caught going over the deco limited due to spending some time on a specific object with my camera and get caught-up in the moment. I have never really seen that as a massive dangerous situation, especially not in an area you know very well and a buddy you fully trust and knowing my air consumption and trusting my computer.

My old computer used to go into deco when everyone still had 10min left, especially with repetitive diving. That is to a certain extend dependent on the specific divers' profile, but to a larger extend it dependents on the algorithm used. With my new computer I could stay a full 60min watching the beautiful thresher sharks in Malapascua on a plateau, where other people had to go up about 10min earlier. Clearly I am paying more attention to deco now as I understand that my new computer is a lot less conservative compared to my old one. The point I want to make is that deco is not as fixed as some people here try to make it look.

Once you start talking about building up serious deco time, clearly the story changes completely and I understand the extra knowledge and safety measures required. Again, that was the reason I started this thread in the first place, trying to find out more about possibilities to do proper deco dives . As mentioned before, that is not required anymore, but I am enjoying reading all the discussions here and finding out more details about BSAC and CMAS at the same time .

 

[rivers]

Although not taught in the PADI recreational system, I don't fully understand the fixation about the NDL. I understand that if you are on a single tank you don't want to build up massive amounts of deco and go to great depths requiring several deep-stops etc etc, but why is that line so "holy"? When I dive in places like Ambon or Lembeh (with my girl-friend as a buddy, and without students and/or people to supervise) I do get caught going over the deco limited due to spending some time on a specific object with my camera and get caught-up in the moment. I have never really seen that as a massive dangerous situation, especially not in an area you know very well and a buddy you fully trust and knowing my air consumption and trusting my computer.

And this is why you should not be doing dives that involve mandatory deco. What happens if your computer dies? Do you have back-up tables that you have cut using the same algorithm your computer uses? Do you have a back-up timer and depth gauge so you can get yourself out? Do you know how much gas you need to complete all your stops if your buddy has an issue with their gas supply? Do you know your stressed SAC rate?These things are all covered in any course that covers mandatory decompression. It seems as if you do dives, where you don't actually pay attention to what is happening on the dive. You become too task-loaded while taking photos that you don't check your gauges often enough. If you aren't check remaining NDL time, are you checking your remaining gas? And you're an instructor?
Obviously, I have no issue with recreational divers doing dives that require mandatory stops. I think for the serious recreational diver, it's actually a good thing. But, before they do, they need to have an understanding of what it actually means, how much gas they need, how much more trouble they can get into, what different deco models and algorithms mean, how they can be manipulated, and how to get out of the sh*t if it hits the fan.

 

[Errol Kalayci]

NL1983,
I would suggest taking a GUE fundamentals course and then moving on from there. There are GUE instructors down there as well as a local community doing some pretty cool dives.
Errol

 

[fire_diver]

.... When I dive in places like Ambon or Lembeh (with my girl-friend as a buddy, and without students and/or people to supervise) I do get caught going over the deco limited due to spending some time on a specific object with my camera and get caught-up in the moment. I have never really seen that as a massive dangerous situation, especially not in an area you know very well and a buddy you fully trust and knowing my air consumption and trusting my computer.

Right there is very reason you should be staying away from deco. You don't pay attention to **** during your dives, dont plan ****, and just blindly follow a computer which you don't seem to understand.

 

[mathauck0814]

Nobody is saying that deco obligations can be ignored, quite the opposite, CMAS and BSAC are absolutely about safe diving (here are 57 pages of the rules http://www.bsac.com/sdp/) however part of that involves dealing with the reality of independent people going diving. Thus they are trained for the start to do deco dives. Then it is up to the diver to decide what equipment is appropriate for the dives they do. The training (BSAC at least) includes how to figure that out.

In the BSAC system the local club members are directly responsible for their own safety, and the DivIng Officer is responsible that the club dives conform to the Safe Diving Practices. Thus peer pressure encourages doing the right thing.

If serious, regular divers trained by "mainstream" agencies are diving to rules designed to protect warm water, once every few years divers for hurting themselves then that is ok I suppose but there is a place between that and full blown cave or wreck penetration at depth with multiple deco gases and an hour of deco.

So there's a "gray area". OK. Let's take that at its word. In that gray area you're beneath a decompression ceiling and you have only one tank of gas. If something were to happen to the tank o-ring, valve, first stage or any of the LP hoses coming from that first stage and you still had something like 9 minutes of decompression left to do and no buddy in sight, what do you do in your "gray area" training?

You're either of a mindset that breaking that ceiling with "only" 9 minutes is somehow an acceptable risk or you've got to be of a mindset that no matter what you're going to finish out your decompression (thus necessitating a full tech setup and the training to use it). I just don't see how you can say, "it's less than an hour of deco, therefore it's not very serious"

---------- Post added August 8th, 2014 at 06:34 PM ----------

NL1983,
I would suggest taking a GUE fundamentals course and then moving on from there. There are GUE instructors down there as well as a local community doing some pretty cool dives.
Errol

As fashionable as it is to recommend that everyone takes fundies, this doesn't make any sense. Fundies won't take a PADI instructor and turn them into a diver capable of executing a dive at 160 feet with decompression. That's not what that course does. Will the OP come out a better diver? Probably. Will they come out a diver capably trained to do the dives he's mentioned? Not by a long shot.

 

[DuboisP]

So there's a "gray area". OK. Let's take that at its word. In that gray area you're beneath a decompression ceiling and you have only one tank of gas. If something were to happen to the tank o-ring, valve, first stage or any of the LP hoses coming from that first stage and you still had something like 9 minutes of decompression left to do and no buddy in sight, what do you do in your "gray area" training?

dive with a tank having 2 valves, use 2 separated DIN regulators (never had an o-ring problem), train yourself to close the failed valve.

 

[bergersau]

Interesting conversation. I actually fall somewhere into the grey area. I completed the IANTD deep diver course some years ago. That qualifies to 39m on air and simply requires that all mandatory decompression stops are completed. The course I did was strong on gas planning and consumption, planning for gas loss during the dive, deco planning from tables with contingencies and running dives from a printed plan using bottom timers.
Twin set or slung tanks of suitable capacity for redundancy were mandatory.
Skills, see here http://www.aquaticadventures.com.au/dive-courses-melbourne/iantd/deep-diver

I don't see this as true Tec diving. But it's clearly not vanilla rec diving either. It is somewhat in the transition between the two.

Sent from my GT-I9300 using Tapatalk

 

[rivers]

Interesting conversation. I actually fall somewhere into the grey area. I completed the IANTD deep diver course some years ago. That qualifies to 39m on air and simply requires that all mandatory decompression stops are completed. The course I did was strong on gas planning and consumption, planning for gas loss during the dive, deco planning from tables with contingencies and running dives from a printed plan using bottom timers.
Twin set or slung tanks of suitable capacity for redundancy were mandatory.
Skills, see here IANTD Deep Diver | IANTD

I don't see this as true Tec diving. But it's clearly not vanilla rec diving either. It is somewhat in the transition between the two.

Sent from my GT-I9300 using Tapatalk

welcome to the grey area club!