DIR recreational deco?

[d33ps1x]

I was going to chip in but watching the inevitable development of a Cyber Ratio Deco Specialty Course before my eyes is far too entertaining...

 

[filtered]

I was going to chip in but watching the inevitable development of a Cyber Ratio Deco Specialty Course before my eyes is far too entertaining...

yea...do 5 of these specialties and you can qualify for a Master Technical Diver rating

 

[TX101]

Why even have a board if the answer is always, "take a class"?

I agree. Especially on something like deco theory. Remember, when you take the class you get one persons view on how deco works - that dosen't mean it's right.

Theories change with time, which is why we dive with helium now rather than deep air. I'm sure in another 10 years time we will be all be sitting around saying how what we did in 2004 was crazy and we shouldn't have pushed those limits.

I don't see anything wrong with discussing it on the internet, since none of it is written in stone and one theory is no more valid than anyone elses.

 

[filtered]

I agree. Especially on something like deco theory. Remember, when you take the class you get one persons view on how deco works - that dosen't mean it's right.

Theories change with time, which is why we dive with helium now rather than deep air. I'm sure in another 10 years time we will be all be sitting around saying how what we did in 2004 was crazy and we shouldn't have pushed those limits.

I don't see anything wrong with discussing it on the internet, since none of it is written in stone and one theory is no more valid than anyone elses.

I suppose the main concern would be someone not having a proper undestanding of deco theory and the various factors involved, taking what he reads on the internet and starts diving the profiles. Could end up getting hurt.

 

[novadiver]

Why even have a board if the answer is always, "take a class"?

I took a DIRF, and if I had a nickle for every time someone asked a legitimate question on one of these boards and the answer was "take DIRF" and it was something they never even mentioned in my class, I'd, well, I'd have a couple of bucks, anyway.

Anyway, what's wrong with the question? Is GI advocating deepest dive last for recreational profiles, and if so, why? It's not like it's a tech diving question, as if that matters.

This should be moved to the basic dive section so a new diver who just got a c-card could answer

 

[JamesP]

I agree. Especially on something like deco theory. Remember, when you take the class you get one persons view on how deco works - that dosen't mean it's right..

This maybe true of other agency training. My training with prior agencies still sits clear in my mind and yet I ended up taking GUE training as it comes with the highest Q&A that I can find. I hear a lot of other instructors touting their level of competency but not the GUE instructors. They just know who they are. When you take a GUE T1 class you get the real deal as per the agency standards. It is not one persons view. You are mistaken. I have seen a number of instructor teach Tech1 and they are all on the same page.

I don't see anything wrong with discussing it on the internet, since none of it is written in stone and one theory is no more valid than anyone elses.

What I have learnt through GUE has come from doing hard time in the water. Real dives not internet surfing. I did not get the way it is done from discussing it. Yes you have to understand it; but you have to do it to get it. The safest and most practical place to get it is from a trained professional in a structured environment.

I have shared what little I know with some very experienced divers with other training. The fine points get missed and deco schedules get modified in an attempt to accommodate their original diving experience. No one here is doing you a disservice by suggesting you take qualified training from qualified instructors. This is the best advise you can get. You do not want to start experimenting with unknowns. Taking a hit is not a very nice thing. What you are going to do is take this discussion out into the water and chances are you are going to get hurt. The original poster presently decos out on a computer. This is night and day away from what we do.

The advise is to take the training and build the skills required to progress in this kind of diving safely. Looking for short cuts will get you a trip to the Hurt Locker.

I recommend you investigate the rec triox or the tech1 program.

 

[MikeFerrara]

Okay, maybe I just shouldn't even be trying to do this, but I'm trying to sort out what GI3 says about decompression diving and apply it to diving within the NDL limits. In particular I'm trying to sort out statements like these:

" Otherwise, repetitive diving is a good thing, and you should do your shallower dive first and then your deeper one. The stupidity taught in that regard is beyond the pale."

" From a decompression point of view, we have seen that repetitive diving makes no difference, so we ignore the first dive in calculating the second. The only trick is that the second dive should be deeper than or equal to the first, and you can not bounce dive after a dive of any kind. We have done back to back 300's with 60 minute bottom times with no change of deco schedule. However, since the real risk is oxygen exposure, we have discontinued that practice due in the WKPP."

(http://www.wkpp.org/articles/Decompression/repetitive_dives.htm)

So, is my Suunto Vyper being particularly stupid when it penalizes me for reverse profile diving? What kind of surface intervals should I use for dives within the NDL? Should I just stay away from this kind of voodoo?

There's no magic here but I can't speak for DIR or GUE. Start a thread outside the DIR forum and I'll discuss it more but for starters don't get confused by some of the stuff GI has written.

I don't have any links but I've seen several "minimum deco" charts published.

The 120 rule is just a way to know NDL's without having a table in your pocket so you can use that or if you happen to have the NDL's from your favorite tables memorized you could use those also.

Plan the dive based on a profile depth which could be anything from your max depth (like you were taught) to an average depth or anything inbetween that you are comfortable with.

Do some minimum decompression for every dive along with nice slow ascents.

For a second dive do it the same or maybe add 10 ft or so to your profile depth if it makes you feel better depending on the nature of the dives and the SI.

Play with some decompression software and tables and you'll see that these things combined will work just fine.

When in doubt check yourself against some tables or software.

The mysterious ratio deco is just about as tricky as this. LOL

Again I'm not speaking for DIR or GUE but this is pretty much what I do.

 

[cornfed]

I don't have any links but I've seen several "minimum deco" charts published.

You mean something like this?

http://dir-diver.com/pdf/minimum-deco-tables/english_imperial_A.pdf

Also available in metric and Swedish!

 

[TX101]

This maybe true of other agency training. My training with prior agencies still sits clear in my mind and yet I ended up taking GUE training as it comes with the highest Q&A that I can find. I hear a lot of other instructors touting their level of competency but not the GUE instructors. They just know who they are. When you take a GUE T1 class you get the real deal as per the agency standards. It is not one persons view. You are mistaken. I have seen a number of instructor teach Tech1 and they are all on the same page.



What I have learnt through GUE has come from doing hard time in the water. Real dives not internet surfing. I did not get the way it is done from discussing it. Yes you have to understand it; but you have to do it to get it. The safest and most practical place to get it is from a trained professional in a structured environment.

I have shared what little I know with some very experienced divers with other training. The fine points get missed and deco schedules get modified in an attempt to accommodate their original diving experience. No one here is doing you a disservice by suggesting you take qualified training from qualified instructors. This is the best advise you can get. You do not want to start experimenting with unknowns. Taking a hit is not a very nice thing. What you are going to do is take this discussion out into the water and chances are you are going to get hurt. The original poster presently decos out on a computer. This is night and day away from what we do.

The advise is to take the training and build the skills required to progress in this kind of diving safely. Looking for short cuts will get you a trip to the Hurt Locker.

I recommend you investigate the rec triox or the tech1 program.

What I was saying in my original post was this:

Nobody on earth knows what the best deco theory is.


Just because GUE have the highest standards of training for SCUBA dosen't mean they know more about deco theory than anyone else.

Everyone has a theory on deco and no one theory is any more valid than anyone elses.

 

[Green_Manelishi]

Okay, maybe I just shouldn't even be trying to do this, but I'm trying to sort out what GI3 says about decompression diving and apply it to diving within the NDL limits. In particular I'm trying to sort out statements like these:

" Otherwise, repetitive diving is a good thing, and you should do your shallower dive first and then your deeper one. The stupidity taught in that regard is beyond the pale."

" From a decompression point of view, we have seen that repetitive diving makes no difference, so we ignore the first dive in calculating the second. The only trick is that the second dive should be deeper than or equal to the first, and you can not bounce dive after a dive of any kind. We have done back to back 300's with 60 minute bottom times with no change of deco schedule. However, since the real risk is oxygen exposure, we have discontinued that practice due in the WKPP."

(http://www.wkpp.org/articles/Decompression/repetitive_dives.htm)

So, is my Suunto Vyper being particularly stupid when it penalizes me for reverse profile diving? What kind of surface intervals should I use for dives within the NDL? Should I just stay away from this kind of voodoo?

Missing in too many of the questions and responses re: WKPP, GI, JJ, etc. is the cold hard truth that GI, JJ, etc. have beaucoup dives and experience in determining what works FOR THEM.

What works for them might get most us bent or killed.