Another Tables vs. Computers Thread

[LSDeep]

guess it is one of this endless threads again with 2 (or more) die hard fractions. after the nitrox without math, now the table or computer version.

i am sure most people on here (even the computer proponents) understand the math behind it (if there really is any - considering that it is all a wide field of "models" with very little proof in reality, beside that people get bend or not). but using tables and doing the math with a sliderule is just sooooooo 1995 (or any year you choose before 2006). your table uses 12 compartments, my computer 18 and my friends desktop software 32 (or wise versa - mix it as you like) is absolutely meaningless as long as your name isnt haldane, buehlmann or (god forbid ) wienke. most people seem to have a problem to recognize the fact that most of the tables and computers are based on the same math models (and their derivates and minorly modified models). the computer is just the logical progression from diving and find out to there are tables to there are decometers to divecomputers to nitrox and trimix capable computers to desk / laptop or pda software. same s**t different format. with the progression of technology and science it gets more convinient and easy to use. the "need to understand the underlaying science" discussion is friggin bs for most ppl (jeez include me) anyway. doubt there are to many ppl on here, that have HARD evidence of the right or wrong of any of this models.
tables get recalled, so do computers or deco software versions (see padi tables, recently Versa Pro revision 2A Dive Computers or the much argued abyss software). the argument that a computer can fail is meaningless! i would be bold enough to claim that the possibility of human error while using tables is indefinatly higher. the backup computer with tables will not work for most people, since using a computer to its possebilities would make the "backup" with tables in most real world situations non workable. that would leave you with a backup computer (not so outlandish anymore, you can pick it up at ebay for the price of a padi wheel).
one of the late introductions to diving / deco theories was the rgbm model (got me bend just once - lucky me). another fastly embraced and now widely accepted model for computers AND tables that seems to work halfway ok within rec - no deco diving but seems to be rather questionworthy in more challenging dive situations (i guess i am not alone there - or call it the least challenged person cause i dont do this kind of dives that regularly ). to read more about it: http://www.inspired-training.com/RGBM Really Good Bends Model.htm )

so whats better?? no clear answer! it both works. some ppl will embrace new technologies faster others maybe never. i am sure there will be still ppl around calculating (or trying to) dives in 20yrs with tables (and use scubatanks) when the rest of the world moved finally on to software and rebreathers. nothing wrong with some historical conscious divers , but hey its moving on. we dont dive with converted fireextinguishers anymore and dont make wet / drysuits ourselfs in the basement, we went from seahunter to dirk pitt as heros and aqualungs twohose regs to xxx (insert your reg of choice - but not the remake lowperformer new twohose aqualung).

ok done now - beat me

 

[MikeFerrara]

This seems to be the most common problem --- you, Mike Ferrrara, and limyx all have reported this as being the big problem with computers.

When you were diving with a computer, when it was set to the proper mix, did it ever restrict your profile?

The only legititmate complaint I've seen about dive computers forcing a diver into an unwanted profile was a Suunto computer that wanted to see 3 minutes total stop time between 20' and 10'. The particular diver preferred an approximation of a 10fpm linear ascent to the surface, with 1 minute at 30', 20', and 10' so the Suunto was a minute short on stop time. (One can argue whether or not the straight line ascent is anywhere near the ideal shape of deco, but in any case, that's what that diver wanted to do).

-----------------

Good summary of points. I propose another one -----

Does diving with a computer force you to do a profile other than what you would do without it? No.

There are lots of reasons that I don't use a computer.

One is that like some one said...to apply anythgin new (or to have a computer that will) you have to buy another one. Not a big deal because if what you're doing is working, you may not need anything new.

Fo diving within "recreational limits, I just don't need a computer...for anything.

I can't say about all computers but I never liked the displays on any of the ones that I used. They just dosplayed things like time remaining (that I wasn't so concerned about) far more promently that the things that I did care about like depth and time. In some cases making the things I wanted to read a little difficult.

Once in decompression mode, many computers display a cieling and a total ascent time. I want t see or know the whole schedule. Sure you could get that from another tool or planning mode but once I've done that I really don't need the computer.

Then there''s the fact that the documentation that comes with computers isn't always very clear about what model or model modifications it's using.

Since I stopped using them, Ive never felt the least bit hindered or felt any need or desire to go back to using them.

 

[MikeFerrara]

That's not entirely true, now is it? Don't they rely on Deco Planner and what not BEFORE the dive? It still smacks of a lot of ego to me: you don't but you do type thing.

NO. GUE may teach the use of decoplanner in their classes but that's not what GI and JJ do (or did). I use the palm version dplan and I don't think it will even calculate their longest dives. It would have you in the water for about a year. LOL

Read GI's articles on minimum and maximum decompression.

You could call it ego but the tools they had before weren't working so they looked for another way. In doing so, they completely departed from the use of a haldanian model and they didn't exactly do it in a haphazzard way either, with people hanging out at the surface with doppler detectors and so forth.

 

[MikeFerrara]

The truly sad part? More people get bent ON computers than on tables. You would think that ANY curricula should cover how to USE these tools competently. Unfortunately, they are villified in the agencies by many who villify them here (or for the same lame-o reasons) and so students never learn the BASICS of computer diving. By denying them the education in the tools they will be using we are setting them up for failure.

But then, I am sure someone will tell them to "just read the manual". This only covers how to operate the device: not how to dive it!

I think more divers get bent using computer only because more divers are using computers. Those same divers who blindly trust a computer would blindly trust a table and get in the same trouble. IMO, the problem is a failure to understand that the model is just a model. They treat an NDL as a dependable line with guaranteed safety on one side regardless of their own physical condition or dive skill and habits. There are lots of "too fast" ascents out there and I think that's what's getting them. In other words it isn't no knowing how to dive with a computer, it's not knowing how to dive period.

However, more and more classes are being tailored for computer use. The PADI nitrox class was remodeled that way some time ago. The DSAT courses focus very heavily on computers. Since I let my mebership drop there may have been other changes too but I don't think any of this is going to reduce the number of divers who are getting bent.

If you're overall dive habits and skills are ok and you're in good shape (fit in the statistical group represented by the mdel/computer testing), I don't see a reason in the world that you couldn't just read the book that comes with the computer and go dive it. As long as you already know how to dive, the computer is just an electronic table where you can't see the whole table all at once.

Besides, I'm sure there are "computer diver" specialty courses.

 

[MikeFerrara]

NAUI teaches deep stops from OW on now. I also emphasize that diving with a Computer should include a 5 minute OR LONGER safety stop.

Computers and tables use SWAG technology to work. They do not measure the N2 absorbed by your body. People who dive need to factor in any mitigating factors as they use their tools. This applies to tables and computers alike. There is no such thing as an "underserved hit". They might not be fully understood, but there was a reason for it happening.

Exactly true as far as I'm concerned. Precise calculation to the foot and to the second are meaningless when you aren't measuring what really counts (inert gas tension and bubble formation) but rather COURSE indicators.

Divers can spend a thousand bucks on a computer and take a class tailored to the use of that computer but we'll have the same old same old until they start teaching divers to control their position in the water...lots of divers popping to the surface from their 70 ft dives and some of them are going to get bent claiming thet the were within their table or computer. The thousand bucks would be better spent on an entry level diving course that really taught diving, IMO

Now before you get upset and think I'm accusing you of not teaching basic skills...I'm not. Maybe you do...I did...and others do...but the agencies don't really require it if you give the standards a good read and so...there are MANY instructors who aren't teaching it because they aren't required to.

Just like in anything else, it's the most basic skills that are the most important because they need to be applied in every phase of every dive. The recreational agencies turn divers lose withought those skills and even make them instructors without those skills. When I read accident reports or the DAN report or even just go diving where there are lots of recreational divers, I see the same things over and over and it always (except medical conditions) comes down to the same basic skill issues...with rapid ascents and buoyancy control issues taking the lead and causing all kinds of problems causing injury, death and sometimes just ruined dives in a veriety of ways.

Until these basics are squared away no one needs a computer or tables because they should be in pool like conditions regarding depth and clearity and you don't need to calculate decompression in a pool. Get this in good order and you could give them a table or a computer and even let them read the instructions on their own and things will go pretty well.

 

[tedtim]

Then there''s the fact that the documentation that comes with computers isn't always very clear about what model or model modifications it's using.

This is the reason why there are so many books available that pretend that they can teach you how to use software or how to program computers in general. Some folks can learn from the book, others need face to face instruction.

I think that this is the basis for all of the discussion regarding computers. It was posted before that reading the manual does not equate to understanding how to use the computer correctly. Same with almost any tool. I have a great new DSLR with a thick manual, but that does not mean that I can compose good photographs. The camera has an auto setting. Same for dive computers. They look really good on your wrist and there are many people that just don't care to know anymore than the basics. If they can use them and not get into trouble for the type of diving that they do, then let them be.

Having said that... without a lot of investigation, I suggest that most people would not know the difference among the various models used in different computers, let alone why the NDLs on tables from different sources vary. So how does the average open water diver choose a computer? I'll bet that it has more to do with a recommendation from a friend or looking at the limited selection at their LDS than comparing what they need for the type of diving they want to do. There is not much on this theory taught during an OW course and probably for good reason. It is not a question of dumbing down during the OW course, but one of informational overload. Sure you can learn the theory and spit it back during the test, but the retention of the theory is questionable at that level of training. Not wanting to get into the "how deep are you certified to dive discussion" I believe there is a good reason for the recommendations made by the training agencies.

Once someone wants to go further they should obtain a better understanding of the nature of the challenge that they face. That does not mean to me that they need to have a detailed understanding of deco theory, how tables were developed, or have to memorize formulas. At a certain point this may be required. I have no problem referring to a reference aid during planning and carrying tables with me. Then again, I am just a recreational diver who likes the opportunity to get away from it all in the relatively silent underwater world. For those more technically oriented types - go for it and good on you.

As for the training issue there is significant added value to going further than the instruction manual if someone wants to use a computer. I don't think that there is as much added value for a detailed understanding of the computer model for an open water diver. Unfortunately, no LDS that I know of offers a course on how to use the computer as part of the sale, let alone how to plan a dive using a computer. So, sell the diver a tool, provide no instruction, send them off. Happy diver with a shiny toy. This is the scary part, not that people use computers, but that they go off without any understanding and use them.

 

[MikeFerrara]

Pride and arrogance (aka ego) have killed more people in this sport than just about anything. IT IS YOUR ENEMY. Only a fool would contend otherwise. But sometimes people just can't handle the truth.

Reading the DAN reports and watching divers has lead me to believe that a lack of skill and knowledge has killed more people in this sport than just about anything. I might use the words "pride" and "arrogance" to describe the approach and apparent attidude of the agencies and many of the people teaching their courses.

GI3 has been known to pull tables out of his butt. So what? You won't catch me following tables built on a gut feeling. That turns a SWAG (Scientific Wild Arse Guess) into a DWAG (Delusional Wild Arsed Guess)! The former is bad enough!

While G13 has certainly employed some unconventional methods, I don't think he's pulled them out of his butt and they work in situations that ather methods were found lacking.

 

[Scuba_Steve]

Au contraire... well I don't know how "you" dive but I can run snapshots. The problem is I get focused enough on taking pictures that I can't do snaphots while I'm taking snapshots, and on top of that I just don't like math as much as I like fish. I am obviously a considerably less gifted diver than "you", but I'm hopeful. I'll just keep at it I guess. Thanks for the nugget of wisdom.

Well you do carry a tank net better than I do. I guess our gifts are just different
LOL

 

[OHGoDive]

Reading the DAN reports and watching divers has lead me to believe that a lack of skill and knowledge has killed more people in this sport than just about anything. I might use the words "pride" and "arrogance" to describe the approach and apparent attidude of the agencies and many of the people teaching their courses.

Not to annoy anyone, but, as a novice diver, I am still gaining skill and knowledge related to these new abilities. There are precious few ways to gain practical skill and knowledge other than to dive. Lack of skill and knowledge, in and of itself, will not kill me. Allowing pride and/or arrogance to compel me to dive beyond the limits of my skill and knowledge is what could very well kill me. Is this the wrong attitude?

 

[boomx5]

Isn't this horse dead yet? There are many different ways to go about planning and profiling a dive. Some use computers, some use software and some use a different method based on Ratio Deco. Personally, I use the later mixed with experience over many dives in different environments at different depths. Is my way better? Yes... for me and my team it is. Is it right for everyone? NO? Not everyone will be interested in putting in the neccessary time, work and effort to learn it. And no, nobody is going to teach you over the internet Charlie.