Skirting the Tables

[jakubson]

So in the end, this diver made a conscious decision while on a dive to blow the tables to watch a group of students. And we wonder why so many new students get hurt and why we agency bash. Agency Bashing occurs because they turn out students like this, that think they can blow the tables for some reason, and then we have a bunch of other divers on Scubaboard that ALSO think its OK. This is a serious problem.

Man, I just may have to pop a new bowl . This is getting good.

 

[JustinW]

seriously lamont, I understand what you are saying from a physiological perspective, but this is about standards and procedures. What you are suggesting is akin to looking at the speed limit on the highway and saying "well i know the turn says 30mph but since i'm in a sportscar I can take it at 70mph" Sure, you might not be mangled at the end of the turn, but there is so much more too it. It is intellectual malpractice to suggest to a new diver to blow off what they were taught in their classes as being too safe.

The diver noticed the max depth when it occurred, but then went on the go over his NDL time when it would have been safer to follow proper training procedures. Remember, any diver needs to follow their limitations, what this diver did was beyond their training. Its not that hard to realize that the answer to the original question is "no this is not good practice" How anyone can disagree is beyond me, given the facts of this case.

The answer to it in theory is that the chances of getting hurt from the event are not super risky, but it still isn't "good practice."

 

[Whitelightnin]

GUYS!!! Is there anything on SB that can be discussed without getting "testy" ? I mean, "Take a chill pill, Man."

 

[JustinW]

GUYS!!! Is there anything on SB that can be discussed without getting "testy" ? I mean, "Take a chill pill, Man."

Sure, lots of stuff, blowing prescribed NDL's without understanding the consequences while others encourage it is not one of those topics. We all like to have fun, but that comes second to safety. Notice not a single insured instructor will post on this subject saying its ok, they would lose their arse.

 

[PerroneFord]

BS. The analogy is more akin to saying the speed limit is 70, and I'm did 75 for 10 seconds... let me go turn myself in to the police. If you get a ticket for 75, you pay the fine.

Is it intellectual malpractice to lie to the diver about the TRUE danger he was in based on what he did? Telling a speeder he needs to follow the limit is good form. Telling him he was facing certain death for going 5mph over the limit is what we are seeing here.

Come on... Yea it was bad. But as Lamont said, the BIGGER danger was having this guy playing around the limits of the table in the first place, but to be honest, it's EXACTLY the same thing people do with a computer. They buy them for the extra bottom time and then ride the limit of them. What's the difference?

Oh, and the NAVY SEALS didn't exist when the Navy tables were made. Not only that, but the actual NAVY tables have been re-written more than once. The recreational tables are based on the same models, but not with the same numbers.

 

[JustinW]

Perrone, remember the question that was asked, "is this bad practice" Yes its terrible practice. Its not OK to say "go ahead and blow your NDL's. I personally never said this guy was in mortal danger. But remember all of the facts and the question that was asked.

You guys can be as risky as you want, there isn't a such thing as being too safe of a diver.

 

[lamont]

seriously lamont, I understand what you are saying from a physiological perspective, but this is about standards and procedures. What you are suggesting is akin to looking at the speed limit on the highway and saying "well i know the turn says 30mph but since i'm in a sportscar I can take it at 70mph" Sure, you might not be mangled at the end of the turn, but there is so much more too it. It is intellectual malpractice to suggest to a new diver to blow off what they were taught in their classes as being too safe.

Its about being a thinking diver vs. blindly following rules. There's a difference between going to 52 for a few seconds and using the 50 foot table value vs. spending the entire dive at 52 feet and rounding downwards. The rule exists primarily to prevent you from doing the latter.

Your analogy doesn't work because really there is *zero* added danger. Really, none. Think about decompression, all you're doing is making the exponential curve slightly steeper for a few seconds over the course of probably 30-60 mins in the water that the curve is operating over. Its like taking a 30 mph curve at 30.1 mph.

The diver noticed the max depth when it occurred, but then went on the go over his NDL time when it would have been safer to follow proper training procedures. Remember, any diver needs to follow their limitations, what this diver did was beyond their training. Its not that hard to realize that the answer to the original question is "no this is not good practice" How anyone can disagree is beyond me, given the facts of this case.

The answer to it in theory is that the chances of getting hurt from the event are not super risky, but it still isn't "good practice."

The scarier thing to me which he wrote in his report was this:

Though I'm safe (not bent) - was this bad practice? Perhaps I should have stayed at safety stop depth for a couple more minutes (the schedule on the NAUI tables calls for a 7 minute stop)? Thoughts/experiences if you have any...

In general a diver with 10 dives needs to back off a bit from the NDL, and not start thinking about adding additional safety stop time for hugging it too close.

 

[PerroneFord]

Perrone, remember the question that was asked, "is this bad practice" Yes its terrible practice. Its not OK to say "go ahead and blow your NDL's. I personally never said this guy was in mortal danger. But remember all of the facts and the question that was asked.

You guys can be as risky as you want, there isn't a such thing as being too safe of a diver.

Agreed.. it's terrible practice. However, I would rather the diver LEARN why it's terrible practice than to have him simply "stick to the tables". Keeping people in the dark is rarely a good idea. Should he ever be in a situation where he CANNOT adhere to the tables (like rescuing a diver from 50ft and having to blow the stops completely) he might be in a better positoin to help himself out by understandind why those stops exist, rather than blindly following the table.

As I said before, all of us make mistakes, and I'd hazard a guess that most people have erred well beyond what this diver did. So let's help the guy gain a bit of knowledge rather than point him down the path of ignorance, and tell him what he did was bad, now stick to the rules.

My tables say I can ascend safely at 60ft/minute from 130 to 15. Does that mean I should do it because "my table says I can"?? My table then says if I spend between 1:48 and 4:48 I will be in the "A" pressure group. What kind of precision is that? A 3 hour fudge factor? Am I really safe at 1:48? If so, why would I wait around nearly 5 hours? And if I really do need that 4:48, why would my table lead me to believe Im ok at 1:48?

The tables are a tool. Not an absolute.

 

[NSDiver]

Wow - well I thought the horse was dead last night, but I see the thread has taken on a life of its own.

To all those with criticism of my original question, "is this bad practice?" - it was rhetorical. I knew it was bad practice - that's why I posted (perhaps I should have been more clear). I posted to make an example of myself and I welcome the criticism. Heck, when I got out of the water, I said to myself "well Nick, you effed, this is going on SB." I hoped it would prompt good discussion.

As for the safety stop, I'll just back off the NDL curve a bit next time to insure I never have to use the safety stop except as a precaution or in case of a problem.

As for the decompression theory knowledge - I'm the kind of person who tries to learn as much about things as possible. I know a bit about decompression theory - certainly not as much as many folks here, but I'd guess more than the average newbie. Perhaps this is an example of "a little knowledge can be a dangerous thing" in that, I knew that because I wasn't diving anywhere near a square profile at a depth of 52 feet, that I would be OK to continue my dive as a 50 foot dive. The practice is still very flawed though, because I didn't execute the dive the way I planned it - and I don't think there is anyone here that has disagreed with that.

I've learned a lot from all of your view points in this thread - I'm glad I'm learning this lesson early when it's potential to harm me is less. I'd much rather get crucified on an online forum than get bent.

Regards.

 

[CIBDiving]

Wow - well I thought the horse was dead last night.....

Oh no, not here! you must be new to SB as well as diving, here they will beat a dead horse to powder, resurrect it and beat it to death again, and then, just when you finaly thinks it's over, some dufus will reopen the thread 3 years later.