DIR equipment: computers?

[detroit diver]

The latest halcyon.DIR catalog I got has a pic or 2 with divers with uwatec aladins strapped to there arms???

go figure :11: and I know for a fact the aladin DOES NOT have the option of being gauge.....it's a automatic on {water contact} dive computer!!!!

Halcyon and their retail outlet ( Extreme Exposure) sell more than just DIR gear. You can buy split fins (or you could) at EE.

 

[StSomewhere]

And, even though mixed gas computers do exist now, these dives still go way outside of their range. Many of the dives are effectively saturation dives and, even if the newer computers allow that much deco obligation to be stored, they tend to way, way overdo the deco on this end of the spectrum. Plus, I don't think there are any computers out there that can handle the number of gas switches.

If you can write a program for a PC to work out things like saturation dives and and gas switches to create tables with, then it you could program a dive computer to handle it too. Algorithms are algorithms, if you would make them match then they'd match. Maybe now that RGBM and the VPM-B are pretty well agreed upon someone could start work on this. I agree that its a good thing to have an analog back of some type (laminated tables, etc.).

The DIR reason for shunning them is more basic. You have no need for it. We don't even carry din covers on our regs. Why would we turn on an unneeded piece of equipment to subject ourselves to its beeping. Carrying a computer in the water is using a crutch to one degree or another. The point behind DIR is not to use the crutch.

Now this may be a valid point. Though pilots have safety systems that warn them when they are out of range on some parameter or another, I'm not sure I understand how something to remind you can't hurt even if you are flying on manual. Esp. when mistakes can be fatal. But then, there's lots I have yet to grok about the whole DIR thing so it doesn't surprise me that this would hard to get my brain around. At a minimum it'd need a much better UI (less task oriented) than you get with the current crop of dive computers.

 

[Diver0001]

If you can write a program for a PC to work out things like saturation dives and and gas switches to create tables with, then it you could program a dive computer to handle it too. Algorithms are algorithms, if you would make them match then they'd match. Maybe now that RGBM and the VPM-B are pretty well agreed upon someone could start work on this. I agree that its a good thing to have an analog back of some type (laminated tables, etc.).

Moreover, some computers do that. The VR3 will have v-planner (VPM-B) in it sometime soon and IIRC the HS Explorer uses a very similar implementation as GAP (RGBM). But even at that you need to understand thta planning a deco dive can involve a lot of modelling and remodelling and refining the profile early in the planning stages. Without PC software i don't know how you would do it. I certainly don't think you can just jump in the water and ride your computer unless it's a dive you've done many times before but then you've already done the modelling in the past.... The real advantage to the computer having the same software as your PC is that the computer will correspond to or be "faster" than the tables you cut on the PC. In that case a computer crap-out will always be followed by picking a depth to "wait" for a min or two until your backup tables catch up with your run time (default back to a sqaure profile). If your computer is "slower" than the tables you cut then you will need a creative solution in the case of a crap-out (in other words, as Richard said, you'd be screwed). For some dives/tables/computers the computer is mostly slower on the last couple of stops so it's not a big deal but for the type of dives and the types of deco and planning the WKPP and others are doing, a slow computer would be more hassle than it's worth. In that context I can really understand the problem and I can really understand the solution they chose. Question is, when will you be doing these kinds of incredible dives?

As for the crutch argument I just don't buy it. Using the computer as a crutch is a choice.

R..

 

[StSomewhere]

No, Diver0001, I won't be doing any of that, not any time soon. I just don't understand why each progression to the next level (OW, nitrox, rec trimix, deco, etc) requires a new and more expensive computer because the old one is now obsolete. Or maybe I'm just starting to see the light...

BTW, even I can see that anyone who simply rides the bars on their computer gets what they have coming. OTOH, I deal with redundant computer systems and disaster recovery sites for a living, so I have a built-in, healthly distrust of the d*mned things. But I still think they have value in providing check figures... YMMV

 

[Diver0001]

No, Diver0001, I won't be doing any of that, not any time soon. I just don't understand why each progression to the next level (OW, nitrox, rec trimix, deco, etc) requires a new and more expensive computer because the old one is now obsolete. Or maybe I'm just starting to see the light...

Well....the obvious thing is what you said, expense. Most people buy simple computers with limited functionality going out of OW because they don't think they'll ever need the functionality of the expensive ones. Gas switching? nitrox? Helium? 10 gasses? Bubble-what? Rebreather? who needs that stuff? Why would you pay for that? They just want to ride their computers and maximize their bottom time. When they hit 50bar the dive is over. Personally I think computers have come far enough that this kind of thing isn't really as big a problem as people make it out to be but that's another discussion.

However, at some point your goals for a dive change. You'll start using Nitrox so you need more functionality, etc. If you have an air-only computer you're SOL .... At some point maximizing bottom time isn't a matter of constantly ascending to stay within the NDL's. You plan to go over and then everything about how you need to ascend changes. And the further you go over and the more types of gas you use, the more it changes. And most computers aren't even working on the assumption that you will go over the NDL let alone in the extremes that some divers do it. Most computers will beep and flash and carry-on at you the whole time you're in deco. My old air computer is hilarious when it gets in deco. If you go through it's ceiling it starts to have what I call "the heart attack", which ends with a long BEEEEEEEEEP reminiscent of a flat-line on a heart meter (that's why I call it the heart attack) and then flips into gauge mode. In fact in heart-attack mode, all the flashing stuff on the screen is so distracting that it effectively masks the only information you really need, namely depth and run time..... Needless to say this isn't the kind of computer you need for deco diving. Is it a bad computer? No but it's not made for those kinds of dives. Delta-P advertises the VR3 as "the only dive computer you'll ever need". Which might be true but it's also one of the most expensive computers on the market and they're a little hard to sell to OW students.

Where DIR is concerned the guys making the rules are looking at the end station. What do you need when you go so far over the NDL that even the best computers are push beyond their limits? Whatever it is, it isn't a computer. So they developed a solution for that problem and since that solution works for less complex problems too the conclusion is drawn that this is how everyone should do it. That conclusion goes a little too fast for me but it certainly has some merit. If you always use the way that you'll eventually need to do the mega-dives then you have less to learn (and most importantly less to *un*learn) as you go.

On the other hand, if you're absolutely positively 100% certain that you'll never do the mega-dives then do you really need the technique that the mega-divers use? I don't personally think so but the DIR answer is still "yes" because the technique works all the time.

R..

 

[Snowbear]

I just don't understand why each progression to the next level (OW, nitrox, rec trimix, deco, etc) requires a new and more expensive computer because the old one is now obsolete.

LOL - the whole point is it doesn't have to.... When I got OW certified I bought the whole LDS gear "package" which included a Suunto Vyper. That Vyper has served me well through Tech training with one simple adjustment.... Guage mode

Cool thing is, once put in guage mode it stays there until you change it to something else. It will work no matter how simple or complex my dives are.

Another cool thing is I can still download it to my PC to get the graphed profiles, which is how I keep my log book

 

[El Orans]

These days I use a bottomtimer on my right wrist and a Suunto Mosquito in my pocket as a digital log book.

Laurens

 

[lamont]

Where DIR is concerned the guys making the rules are looking at the end station. What do you need when you go so far over the NDL that even the best computers are push beyond their limits?

Also, they're doing decompression physiology experiments on-the-fly with every single dive at that point. They don't want to adhere to a given computers model, they want to invent a model that works for their own body.

Whatever it is, it isn't a computer. So they developed a solution for that problem and since that solution works for less complex problems too the conclusion is drawn that this is how everyone should do it.

I don't think they've ever said that DIR works for everyone under all circumstances. However, if you start GUE training, the goal of GUE training is to produce technically trained divers, so they want to start you off so that there's a minimal amount of retraining as you progress.

On the other hand, if you're absolutely positively 100% certain that you'll never do the mega-dives then do you really need the technique that the mega-divers use? I don't personally think so but the DIR answer is still "yes" because the technique works all the time.

I think that DIR actually ignores all the divers you're talking about. Its a technical agency. Take a 63 year old vacation diver who wants to swim around and look at fishes on reefs and not do anything too deep or strenuous, and I don't think GUE really cares. Different problem, not what they're trying to solve.

 

[Diver0001]

Also, they're doing decompression physiology experiments on-the-fly with every single dive at that point. ....snip.....

Good points.

R..

 

[riddler]

I don't think I'm a hound, but I could be mistaken.

The answers to your two questions are "Yes. The use of computers is incompatible with DIR" and "No". There are any number of citations that establish this, PM if you would like details.

Doc

So this leads me to ask the next question: I've been to more than one recreational dive site where the dive operator requires a computer. If the average DIR diver does not use a computer, do you avoid diving with operators that require one?

All in the process of learning about DIR for me :06: Maybe DIR divers don't do a lot of recreational diving at all? Or maybe in that situation, you could rent one and not bother to use it?