Why no computers for DIR?

[Big-t-2538]

MechDiver once bubbled...

And I thought it was against the rules for mods to hijack threads

I think he's going for a genuine pugging here...

look at what snowbear just said about "you can do it by feel"

And as for the saberlight...well...maybe you just got all the defective ones on the market (you know the ones that slipped by QA) and we (the normal people) got the standard pelican product

 

[Uncle Pug]

MechDiver once bubbled...
And I thought it was against the rules for mods to hijack threads

But gotta scoot right now... go buy another Andy's and a couple of E8-130s with all the money I saved by buying Pelican Saberlights.

 

[Snowbear]

Big-t-2538 once bubbled...
I think he's going for a genuine pugging here...

look at what snowbear just said about "you can do it by feel"

I bet if you were to review som of Pug's former posts/threads, you will find he mostly dives by "feel." Im still in the early learning stages of my diving, so instruments help me learn what to "feel" for. I did, however, quit using my pony bottle except for deco.

 

[Charlie99]

Kendall Raine once bubbled...
Here's the DIR logic from the source:

Baker's Dozen for not using a Dive Computer By Jarrod Jablonski


1) Dive computers tend to induce significant levels of diver dependance, eliminating the awareness so common and essential to all diving but particularly obvious when diving tables

I completely agree on avoiding dependence. One should not rely blindly upon either tables or computers without understanding the logic behind them.

2) Dive computers do not allow proper planning as divers can't properly "study" the impact of various mixture and decompression choices.

Huh? I can do all the studying I want, using the same decompression programs whether or not I use a computer during the dive.

3) Dive computers are of very limited educational benefit as they do not induce questioning, or proper planning discussions as can be found with
tables and most particularly with deco programs

I find dive computers MOST educational. The best way I've found to calibrate my own mental tracking of N2 loading is to compare my mental calculations with those of the computer. If I were to never use a computer I wouldn't be getting that realtime feedback.

4) Dive computer programmers often play games with computational process so that they can take insulate themselves from the risk of taking largely square profile data and utilizing it on a multilevel dive. These games tend to result in odd and often ridiculous levels of conservation.

We each have our own level of desired conservatism. Dive computers do a better job at implementing the particular algorithm than my crude mental approximation. The algorithm that many computers use is the same Haldane dissolved gas model used by GUE's Decoplanner, although there are several computers out that use the enhanced dual phase models.

5) Dive computers are expensive and in some cases leave divers with limited resources carrying equipment that is of far less benefit than other equipment that may have been purchased.

I agree that divers should not compromise the quality of other gear in order to purchase a computer. Most do not.

6) Dive computers significantly limit the likelihood that divers will track their residual nitrogen groups.

If this is indeed true, then it is an argument against improper use of computers. Blind reliance upon any tool is unwise.

7) Dive computers do not allow for Helium diving in any formats but the bulkiest and most questionable format.

Irrelevant to typical recreational diving. Others can comment on whether this statement is still true for tech diving.

8) Dive computers will often generate longer decompressions than could be figured by an astute, well educated diver with experience.

It is too bad that GUE is not willing to document and distribute this astute well educated experience by including these decompression profiles in their Decoplanner program. Meanwhile Bruce Weinke is working with various manufacturers to implement full-up RGBM in computers. For recreational divers, though, this issue is not relevant.

9) Dive computers often create confusion by giving the user to much useless information, sometimes even obscuring depth and time in favor of blinking CNS and/or deco limitations.

This perhaps is true of some computers, but not with the ones I am familiar with. My computer shows both NDL, graphical N2 loading as well as the more basic runtime and current depth info on the same screen. I find the task loading of knowing which number is which to be acceptable.

10) Dive computers can become very difficult to properly if a deco stop
has been violated. Some computers lock up completely while others just beep or generate erroneous and distracting information. Divers using mixed gasses are likely to often violate computer profiles.

I have never heard of a computer locking up while still in the water. Many, if you violate them, will lock up several minutes after you surface. I agree that it doesn't make sense to do deco dives with multiple gasses and attempt to track it using a single gas computer. This is clearly misuse rather than a problem computers in general. Get the right tool.

11) Dive computers do not allow for the educated diver to properly modify their decompression to account for advancing knowledge such as the use of deeper stops in a decompression profile.

This, along with "computers don't give credit for deep stops" are two common red herrings. A computer that indicates a ceiling depth of 10' does not require that you immediately ascent to 10' anymore than a mental calculation that you are approaching NDL says that you need to rocket to the surface. I routinely use deep stops while using a computer. The computer properly shows that the faster tissues have offgassed, while the very slow tissues have taken on some additional loading.

12) Dive computers do not offer divers as much flexibility in the generation of profiles with varying conservation. For example the right mix would allow 100 min at 60 vs 60 at 60 but I might prefer to do one or the other and indeed might like a compromise. Computers confuse this issue by not providing divers with the proper information.

I don't understand this comment. Dive computers don't generate or control profiles. They are accounting machines that track what has occurred and report the results. I can dive any desired profile.

13) Dive computers users often ignore table proficiency and therefore do not learn tables properly. When confronted with a situation where they can't dive the computer (failure, loss, travel etc) these divers are at a serious handicap.

That some divers improperly rely upon or improperly use a tool is an indictment of those divers, not the tool.

 

[Kendall Raine]

Sweeping the silly posts aside for a minute, the debate here seems to come down along the lines of those who believe all available technologies should be employed in the interest of dive safety and enjoyment and those who argue that using all available technologies bears the price of potential dependency (through laziness) on a fallable or limited/inaccurate technology.

I think it's important to recognize that most people here come to the debate from the perspective of "recreational" diving wherein dive computers have enjoyed an established and viable place in people's gear package and consciousness. They are generally "reliable" and affordable. That's juxtaposed by the perspective which evolves from the technical community where, for various reasons including lack of helium based programmability, antequated algorithms, dependability issues and streamlining, computers have never gained the same level of acceptance. There are those who have always dived recreational profiles who have never used computers, but I see them as somewhat tangential to the warring factions.

When trimix was first appiled to sport diving in the late 80's in the Florida cave community, nitrox and trimix computers weren't available. Computers couldn't handle switches. They all had various neo-Haldanian models hard wired. These air computers were obviously useless for mixed gas deco and trimix tables were available from only a very limited number of hyperbaric specialists like Bill Hamilton. Frankly, any sport diver who used trimix before the late 90's basically had to use either specialist tables, custom generated schedules (typically PC based) or tables of various quality available from the training agencies. Even those diving deep air (eek) and decompressing on elevated O2 were stuck until programmable multi-nitrox computers became available in the mid-90's. For those divers, using custom (mix/time/depth) specific schedules together with a bottom timer was SOP. As some of those divers started experimenting with different schedules for the same mix/depth/time parameters, they realized that there were ways to reduce deco time from set model terms without increasing either bends rate or post dive bubbles. The most radical of these departures was done by WKPP of which some of the early GUE guys were/are members. At the same time, dual phase models started becoming widely available to technical divers which offered a more elegant and robust theoretical structure for decompression management. Best of all, these dual phase models worked. Computer implementations of dual phase models is no more than about three years old, however. Functionality of some of these devices is still highly questionable. The point of this is the technical community, from which comes so much of what GUE teaches, really grew up with bottom timers and experimentation with various schedules. For these people, it's relatively easy and intuitive to apply that type of thinking to recreational profiles-even repetative ones. Looking the other way, from the recreational perspective, it seems ludicrous, anachronistic and artificial to chuck a device which 1) seems to work, 2) saves bandwidth in the brain and 3) really doesn't cost all that much relative to the overall costs of the sport.

As such, what seems to keep coming up on the one hand in these debates, other than the tired "you can't tell me how to dive" whine, is the attitude of "if they (computers) ain't broke, stop contriving reasons to give them up." To the people who come from a technical background, and for whom bottom timers and schedules have been a way of life for years, this argument seems lazy and stale.

I don't think either side will cause many on the other to convert. Diving with a bottom timer does require more awareness and commitment to understanding physiology and decompression theory. Those drawn to those subjects will more easily grasp and enjoy the advantages of timers and PC based alogrithms. Many for whom a computer accomplishes the job from a function perspective may never want to take the time to focus on the issues enough to give up their computers. It's a bit like those who want gauges in their cars as opposed to an array of warning lights lights. Attempts by one side or the other to denegrate the other will only solidify the respective sides in their positions and misses the point, anyway.

Apologies to going on, but I hope the historical context might make the debate slightly less two dimensional.

 

[DeepScuba]

Thanks for breaking down the Bakers dozen for me Charlie.

I almost did it last night when I read about it here, but you did a better job than I would have. I basically feel almost all 13 reasons are chalked full of feeble attempts to marginaly explain away a problem that doesn't exist.

Point.........Computers aren't THAT expensive. A few hundred dollars at most, unless you want the kitchen sink thrown in. A couple hundred dollards is Jack-$hit compared to the rest of my gear and training course. SIMPLY, the 2-3 hundred dollars in reality, is irrelevant.

Ditto for the computers rotting your brain comment. AS one astute fellow proclaimed here, computer don't do squat to your brain......YOU DO. Sure they can make it easier to be "Lax", but then, so do BC's and pressure guages! Saying that people with computers have a brain that is idle, is just plain painting a whole lot of good diver with a black brush.

So she's down to a Bakers 10.......

He then goes on to explain why he's far smarter than, evidently every decompression modeller/scientist..........JJ you kill me!!!!!

He should really give it a rest with the lame attempts at stretching marginal aspects, into full blown "the sky is falling" Quasi-Facts he purports.

Good for a read, but most can descern fact from stretched opinions.

Bottom line, computers nerver get narced, even on a bad day. If they fail, you still have your brain, which is probably still working. You still have your tables as well.

I doubt computer programmers play "games", with liability being what it is........and JJ, what's wrong with rediculous conservatism anyways???

So you're saying you 120 rule is "riskier"???

Why would I do that?? Why would I dive trimix to 120ft, and then run a risker profile??

Kinda mutes the Trimix over 100 idea doesn't it?? I really feel that the narcosis/nitrogen loading on 120ft dives is marginal, and trimix, although I like it theoretically, just ain't practical.

For that matter, take the money I would spend on Trimix on my over 100 ft dives, and I'd have a killer computer in no time!!!!


Just food for thought guys........Don't start the flamer war.
I'm just saying, doesn't some of these point seems to be pushing the envelope of believability?

Regards

 

[BigJetDriver]

Uncle Pug once bubbled...
[B...OK... for you aviation buffs and bus drivers who want to mix apples and oranges:
What instruments would you need to land an ultralight on a frozen Alaskan puddle? [/B]

Well, let's see, I really, really don't enjoy freezing my cojones off, so I wouldn't be using an ultralight. I'd be flying a Maule Rocket, or a Zenair 801, or a Sherpa, if the ice was thick enough. They come with whatever complement of gauges you feel are necessary, so, yes, as you might imagine, I would have the full-house set.

However, just as it is with the big stuff I drive, the last few feet (in VMC) are done by "highly-calibrated eyeball". And, yes, I have a feeling I know where you'll be going with that last comment! =-)

 

[Charlie99]

DeepScuba, if you look at my previous post and apply to it the comments just made by Kendall, you will see his analysis accounts for virtually every difference between my statements and JJ's. A lot has to do with whether you treat recreational diving as an exciting and enjoyable activity in its own right, or as merely a stepping stone to tech diving.

I don't REALLY have that big of difference in mindset from what JJ is saying. People that blindly rely upon computers are idiots. I just don't extrapolate that to saying that people that use computers are idiots. The same people that misuse computers are also likely to misuse (or just flat out ignore) tables.

Some of the lameness of JJ's Bakers Dozen is that he was trying to copy the model of an earlier writing by George Irvine of a Baker's Dozen reasons of why to use 100% O2 rather than 80/20.

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

Several months ago, in response to some posts that were claiming computers were simply crutches needed only by weak, incompetent divers, I posted (in jest, but without smilies) something along the lines of "it is dangerous to rely upon unreliable equipment like depth gauges. A truly competent, skilled diver will simply use his ears and small objects in the water to be aware of changes in depth. Then by simply mentally tracking on the fly the depth changes the skilled diver will be fully aware of his depth at all times. Depth Gauges Rot Yer Brain!"

The funny thing is that several people took it seriously!

 

[MikeFerrara]

I'm not "against" dive computers like some people but I don't seem to need one. I do dive a lot of helium, though, so all the computers I have to look at are $1000 and up. That's a week of cave diving in Florida (for the family), or a three day trip to the Kamloops, or another set of doubles, a 1 week trip to Akumal and it's a whole bunch of helium and oxygen. I just can't see what I'd be doing after buying the computer that I'm not doing now.

As for my local recreational fun dives, I sure don't see how a computer would change those.

 

[BigJetDriver]

Snowbear once bubbled...
Eyeballs help, as does an altimeter if your depth perception is a bit off or the light is too flat. When you're learning, it helps to know your air speed, but after a couple dozen landings, you can do it by "feel."

Someone said ground lights - not *supposed* to be flying those things in the dark. Besides, most of the frozen tundra puddles aren't on the grid

Good point, Snowbear! We in the pilot ranks enjoy doing it by feel! We make landings that way as well!!!