Does not compute but should I ?

[landlocked]

SeaJay once bubbled...
In my experience, DIR-F did not teach deco theory. (My experience was the same as O-ring's.)....
What I do know, and have resisted sharing, is the simple technique to calculate your No Decompression Limit "on the fly." ....

But O-ring said...

O-ring once bubbled...
Maybe my class was especially bad and we all failed so miserably that we didn't make it that far (we also didn't do any liftbags). Anyway, for whatever reason, that was not covered.

So now I'm confussed. You say that if I want to learn to compute NDL on the fly I need to take DIR-F, then O-ring says he didn't learn it in his class and now SeaJay says his experience was the same. So where do you learn it? I'm so confussesd!

 

[gzscuba]

So, I generally really perfer the open exchange of ideas, but the water gets a little muddy... or silty , when you consider that some information, if used incorrectly, can get someone hurt or killed. Unfortunately, I'm sure that there are some new divers on this board who might see a description of an "easy in-your-head NDL tables" method, try to use it without a good backup or precautions, and get hurt. Seajay, I'm assuming that during DIRF, they somehow quizzed you on your NDL while you were underwater to check that you had it right. Trying to use that technique without some good training, or at least practice with a backup source of NDL info could certainly be dangerous.

As for me, I'm task-loaded enough just trying to adjust my height in the water, and would probably lose track of an NDL in my head, no matter how easy the heuristic is. I'm going to stick with tables for the time being and probably purchase a computer at some point.

My interest in decompression theory is mostly a scientific curiosity. I'm a scientist & I like to ask questions so I can understand what's going on in my body and the world around me. Some day I might be able apply theory to better track my N2 loading underwater. Then again, it probably won't happen.<shrug>

 

[gzscuba]

So I'd like to explore the whole computers rot your brain thing. I'm sure it's been gone over in the past. Links to old threads are welcome. Aside from the fact that some people can calculate NDL's in their heads making computers unnecessary, I've heard the following:

First, don't most computers allow you to do a repetitive dive deeper than your first dive. Some people may say that this is okay, but I thought that most of the agencies frown upon this.

Second, I can see how someone might use the ascent meter or tank-time-left indication (on air integrated units) as a crutch so that they don't pay attention to the total gas remaining, or the use of landmarks or Uncle Pug's mysterious "stuff" to track ascent progress.

Comments?

 

[sea nmf]

You know, I would have to agree. In general, all computers used for calculations (retail stores, auto stores, etc.) rot your brain. Just see what happens to people when their computer breaks!

That being said, I am a computer user. I am fully aware that the "table calculation" will not be in my head should my computer fail during a dive. I can use the tables for a square profile for future dives.

However, if my computer fails on a dive, and I am "situationally aware", then I will know how to end the dive safely.

So, yes, computers rot your brain (IMO). But do I think I want to throw all computers out (diving or otherwise)? NO!!!

If you want to calculate your income tax obligation in your head, I think you are fabulous, brave, and a genius. But I'm going to use a calculator.

-becky

 

[O-ring]

landlocked once bubbled...
But O-ring said...

So now I'm confussed. You say that if I want to learn to compute NDL on the fly I need to take DIR-F, then O-ring says he didn't learn it in his class and now SeaJay says his experience was the same. So where do you learn it? I'm so confussesd!

I think they showed us something in DIRF that we could use in case of computer or table failure for recreational dives. It wasn't anything new or proprietary, but was simply the old Navy 120 rule. I think the rest of this depth averaging stuff people learned on *GASP* the Internet. There have been too many threads on other lists/forums about this type of thing for me to not believe people learned it from reading stuff posted to other boards. If not, I stand corrected...but I think most people learned it on the Internet. I am also pretty sure they teach it in Tech 1....so maybe people learned it there. They don't teach anything like that in DIRF to my knowledge..

First, don't most computers allow you to do a repetitive dive deeper than your first dive. Some people may say that this is okay, but I thought that most of the agencies frown upon this.

Yes, most agencies frown on doing this...it is called a reverse profile.

 

[gzscuba]

sea nmf once bubbled...

However, if my computer fails on a dive, and I am "situationally aware", then I will know how to end the dive safely.

So, yes, computers rot your brain (IMO). But do I think I want to throw all computers out (diving or otherwise)? NO!!!

Darn - I knew there was something that I forgot to mention in my post.

I think as long as you keep planning your dive according to the guidelines from your certification agency, and practicing your skills, you should be fine. It seems like the people that get brain rot are the ones who depend on the computer to think for them.
I certainly hope that mere presence of a computer doesn't cause your brain to go poof!:wacko:

 

[MikeFerrara]

landlocked once bubbled...
It is probably the best way, but it is so subjective. I dive with tables, strictly NDL. But I also try and pay close attention to how I feel after a dive. As a result, I now make sure that I am well hydrated, well rested, use Nitrox whenever possible and eat well before and after diving. But doesn't this thinking lead to getting bent at least once. How do you find your limit if you never get bent? I would like that limit to be set some other way than finding out that I don't feel well "after" a dive.

Speaking for myself and the diving I do...I'm not trying to find my limit. What I want to know is whether or not what I'm doing is working.

 

[MikeFerrara]

SeaJay once bubbled...
Okay, a real quick note here...

In my experience, DIR-F did not teach deco theory. (My experience was the same as O-ring's.) Furthermore, I am not qualified to talk about deco theory. I am not yet a deco diver, and all that I know about the subject is what I've learned on my own accord by going and seeking the information myself. Until I receive that training, though, I refuse to dive with a deco obligation.

What I do know, and have resisted sharing, is the simple technique to calculate your No Decompression Limit "on the fly." Since most manufacturers of computers (even those capable of calculating deco) recommend staying within NDL's, ....

...snip...

That's why I recommend that people take the DIR-F course if they want to know the procedure. It's no big magic... Just a simple rule that gets you a fair degree of accuracy with some math simple enough to do in your head.

wait but you said...

I paid a lot of money for the information, to say nothing of the time and effort investment.

Am I reading this post right? I think it says that DIRF doesn't teach it but if I want to learn it I should take a DIRF

Did you learn this in DIRF or not? If not where did you learn it? Forget the what I'll settle for the where.

BTW, I thought there wasn't any such thing as a technical dive (or they all are technical) and that all dives are decompression dives and now you say you stay within the no decompression limits? I thought there wasn't any difference.

 

[SeaJay]

MikeFerrara once bubbled...


Am I reading this post right? I think it says that DIRF doesn't teach it but if I want to learn it I should take a DIRF

There seems to be some confusion on what "it" is... We were talking about why DIR preaches "no need for a computer." If a diver wants to learn that, then yes, I'll recommend DIR-F. Now, however, "it" has become actual "decompression techniques," and no, they are not taught in DIR-F... They're taught in other GUE courses, which have DIR-F as a prerequisite. Either way, I maintain that if someone wants the information, then they would want to take the class. If they prefer not to, then fine. It doesn't matter to me either way. I'm not selling DIR-F courses.

Did you learn this in DIRF or not? If not where did you learn it? Forget the what I'll settle for the where.

BTW, I thought there wasn't any such thing as a technical dive (or they all are technical) and that all dives are decompression dives and now you say you stay within the no decompression limits? I thought there wasn't any difference.

There was a pretty big thread not too long ago around my writeup on DIR-F. AndrewG and MHK were my instructors.

I took DIR-F in Atlanta. Our quarry dives for the weekend were in Alabama on the same weekend of the shuttle disaster.

For the record, I have never claimed to dive beyond the NDL's, and that was exactly my point above. Yes, I also said that there is no difference between deco dives and no-deco dives. Your body decos either way. It is true that the term "technical dive" is a misnomer. They're all technical... At least, that's my opinion. Saying that there is a "higher order" is an opinion thing, and I don't beleive there is a "higher order" of diving. If you do, then feel free to have that opinion. It doesn't matter to me.

Enjoy your dive.

 

[MikeFerrara]

SeaJay,

I'm not trying to put you on the spot. From what you and said I got the impression that DIRF will teach a diver how to calculate their NDL for a multilevel dive on the fly and without a computer.

My mistake I guess, sorry.