PADI tables finally going away?

[John_B]

But if we really knew under what precise circumstances a particular diver doing real-world multilevel dives would develop DCS with a high degree of accuracy, and if you could measure all the related parameters, and if you had a computer that could factor in all the realtime data and crunch out a genuine NDL number, then why wouldn't you be able to "ride" that number? Aside from reserving some amount for contingency, you wouldn't need to worry about it.

But right now that's all some sci-fi future; we have to deal with the imprecision of what we have now, goats and pigs and bent Navy recruits and all.

But then we'd need inputs on how well they were hydrated on the flight down yesterday, and how many beers they had at the bar once they arrived, and how much REM sleep they got last night, and what is their actual body fat ratio, and do they have good air consumption, and how much of that is due to their higher-than-necessary metabolism (because they fin and skull their hands like crazy), and how much do they bounce around all over the water column vs. just hovering at depth, and any number of other factors I can't think of off the top of my head.

So we're never going to get something exactly precise that a new diver is going to be just follow with the brain cells in neutral and "guarantee" (in the legal sense) that they aren't going to get themselves bent.

Worse, due to those legalities we get a bunch of dive computers with a bunch of extra conservatism built-in. And how that conservatism is calculated becomes this big, proprietary, trade secret for each computer; sometimes even with a mathematician (cough, cough, Wienke, cough) as a paid endorser.

And eventually these new divers become convinced that simply flying these "conservative" PDCs to the NDL with no dive planning will "keep them safe" or "keep them from being bent".

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I reached a point where I will only dive with/buddy up a new diver if I've been able to have a discussion about buddy diving and basic gas planning. I guess if PADI is going to punt on this (and it sounds like they already have) then I'll have to add basic dive planning to that discussion. I hope it's a long enough boat ride out to the dive site.

 

[likestodive]

I consider myself fortunate to have been taught the tables in depth. I took an interest in them and studied them hard. I think it gave me a greater understanding of what actually happens to a diver.

That said, I think new divers are best served by teaching simple repetitive dives via the tables and discussing in basic terms what is going on (ndl, rnt, etc) and then emphasize how to read a simple computer computer layout. I use oceanic stuff and find it very easy to read. Realistically, most divers these days are going to be diving with computers and should be taught how to dive with them. I have seen quite a few divers that didn't seem to have a clue on how to read their computer.

I'm sure we can all agree that the standard 'you don't need a dive plan just follow the divemaster' is a bunch of hooey. I'll trust my computer and brain over the divemaster any day.

I also don't agree that somehow dive tables are safer than computers for decompression diving. Yes, computers use mathmatical models instead of actual nitrogen loading - but so do tables. Most of them also tend to get very conservative if you start doing alot of decompression diving, 'yo yoing', etc. I view that as a good thing.

I keep a table in my BC out of habit. I prefer my computer any day. Yes, I've had computers die on me before. It IS a risk of diving with computers but so be it. I always managed to somehow find another for the next days diving and was able to use the tables for the remaining days dives though I didn't get as much bottom time as I would have liked (and yes I know the computer didn't take all my RNT into account for multiple days, etc).

 

[terrylowe]

Well, I'm a dive computer guy. Tables are great and are a good teaching tool and helps teach the theory. Although I don't have the experience you 2000+ dive folks have, I still haven't seen anyone use a dive table prior to a dive. I HAVE seen more than one person get in the water without a clear understanding of how their computer works or even turns on. If more people are going to use computers, then we need to do a better job of trying to teach them to use it....rather than a passing one page discussion in the OW book.

 

[Kingpatzer]

Tables are . . . a good teaching tool and helps teach the theory.

You'll note that quite a few instructors and at least one educational professional disagree with both of those points throughout this thread. Everyone is of course entitled to their opinions, but from the perspective of education research you'll note that studies and practical experience have been offered as relatively objective evidence as to the questionability of those claims.

If more people are going to use computers, then we need to do a better job of trying to teach them to use it....rather than a passing one page discussion in the OW book.

There is universal agreement on this point here, at least.

 

[DiveNav]

...... If more people are going to use computers, then we need to do a better job of trying to teach them to use it........

.....There is universal agreement on this point here, at least.

There is agreement on this point ... and not only on SB!

So far we have released classes for 20 dive computers ... and more are on the way.

Several retailers are already offering our classes and some manufacturers are moving forward to include our classes with their products.

Logical next step is to work with certification agencies. Stay tuned

Alberto (aka eDiver)

 

[LakeCountyDiver]

I like this it is a good discussion. I think they really need to teach the tables. Every computer is programed with the same knowledge (TABLES) no matter how much you payed for it. They all run off the info they are programed with. What makes most computers different is the features and options but the math is always the same.
The tables need to be #1 in class because it is what makes the difference between a good and bad dive. You're tables can't malfunction but the computer can. If you dont know you're tables how can you tell if the computer is out of wack.
Diving with computers is a specialty, asking to take tables out of the class is crazy. I think if any student buys a computer an instructor will have no problem teaching him how to use it. He/She does need to know the tables.

 

[mikecotrone]

I recently took the ediving online class for my Oceanic VT3. It was excellent and filled in a bunch of holes that i had from using my computer and from reading the manual. I think anyone that has purchased a new computer and if ediving has a course it is a wise investment of 8 dollars IMO.

 

[drrich2]

You're tables can't malfunction but the computer can.

There's a serious flaw in this logical argument. The tables aren't acting as an equivalent to your computer, so you can't compare directly as such.

Your mind & senses, working with and interpreting the tables, is what is taking the place of the computer when you dive tables. And the odds of your mind miscalculating/getting off on the wrong row & times/pressure groups (i.e.: 'malfunctioning') is probably a lot higher than the odds of your dive computer malfunctioning.

As for a knowledge of dive tables enabling you to 'pick up on' computer malfunctions you otherwise wouldn't, well, maybe. But because most people don't spend most of their time at their maximum depth, and most table usage works as though you do, most divers are accustomed to their computers giving them way more NDL time than the tables anyway, so what are the odds they'll really notice?

I had to learn the tables when I took PADI OW & (modified, of course) Nitrox, and I'm not 'anti-tables,' but the logic I see in some of the arguments on the thread has some holes.

Richard.

 

[Paladin]

I recently bought an Oceanic Veo 100 computer and I've dived it a few times. I still plan my dives using tables and I still dive according to the tables. The last two times I went, I just locked the computer in Gauge Mode and used it as a depth gauge and bottom timer with a watch and capillary depth gauge as backups.

I happen to like the built-in, conservative nature of diving a muli-level dive on a square profile. Besides, the majority of my dives tend to have a square profile anyway. The bottom line, for me, is that I simply do not trust computers. I do, however, have confidence in the tables.

 

[dir-sussex]

I'm afraid that, as with a lot of other areas of life, diving and divers are becoming lazy and more importantly, due to the economic pressures of trying to get as many divers through their basic courses at bargain basement cut-throat prices, the professional (i.e. paid for) courses are being 'dumbed-down'.

As with many other divers, when I started my diver training back in the early 1980's with the BSAC, there were very few dive computers available (decobrain / edge) and they were only fro the rich divers. The vast majority of divers relied on depth gauges and wristwatches. This taught us many valuable lessons, which have stood me in good stead in all the following years, namely:

1. Don't trust electronics (they will fail at some point, guaranteed).

2. Every diver should know what to do when electronics fail, so repetitive use of tables and standardising of gasses means knowing what deco you need from memory for every dive.

3. Planning a dive effectively, with your buddy or team, means that you can plan for contingencies together.

4. Dive planning and the correct use of tables is essential for any diver moving towards use of Nitrox or multi-level diving, in order to understand all the issues with oxygen and inert gas tracking, which is crucial for repetitive diving such as on a liveaboard trip.

Training should not be solely about making money from the diving community; it should be about fully equipping divers for their diving career.

Tony Howard
BSAC & SAA Club Instructor, ITDA Technical Nitrox Instructor, TDI Advanced TriMix Diver, IANTD TriMix Rebreather Diver & TDI Advanced Gas Blender