Why the Compass on the Left Arm?

[PfcAJ]

I haven't used a computer since fundies. Modified rule of 120 (for nitrox), 120 for the rare air dive, and I'm in the water longer than some folks with computers. Square profile or not, deep, shallow, long, short, doesn't matter.

 

[LiteHedded]

have I stepped into a time machine and ended up ten years in the past? we're arguing about compass placement and air integrated computers?

I, for one, want to know why I can't use my split fins and why dir divers are so mean on the internet. how do you route your spgs with independent doubles?

 

[TSandM]

LiteHedded, the guy is asking questions about why. We should be able to answer them.

One of the big differences between the way DIR divers dive and the way most recreational divers dive is that we PLAN our gas. We know the proposed profile; we know the capacity of the tank. We have a plan for emergency gas reserves, and we know our consumption rate. So we have a pretty darned good idea of how long we should be able to dive. The SPG, in some ways, is just a double-check on what we already know. When I check my gauge during a cave dive, I know what it OUGHT to say -- if it says something different, it's an alert to let me know something's out of whack, and I need to figure out what it is. Am I swimming against a lot more flow than I realize? Am I nervous? Do I have a leak somewhere that I'm not hearing? Is the gauge malfunctioning? The reason we don't use redundant gauges is that the gauge is a kind of redundancy to begin with.

The argument against AI transmitters is less compelling. They are expensive, and that's money you could spend on gas or dives or training. They are notoriously temperamental, and DIR tends to prefer reliable ("robust" ) gear rather than anything glitchy. And, since the gauge is not something you need to check constantly, if you have done your planning properly, there is little advantage to having the information available on your wrist.

And yes, the majority of us don't use computers for no-decompression information. Again, dive planning is important. And one does have to pay a bit more attention to the profile, which is generally a good thing. The DIR proscription against computers comes from a number of issues. One is to avoid the "magic bracelet" phenomenon, where the diver cedes responsibility for the profile to the device. Another is to avoid the situation where divers using different computers end up with different decompression information. A DIR team will always be together on how much no deco time they have, or in the alternative, on how much deco needs to be done. You have to remember that the use of standard gases makes this all much easier, too.

 

[LiteHedded]

LiteHedded, the guy is asking questions about why. We should be able to answer them.

no i get it...
but i thought we were past the days where 6 pages of back and forth arguing with trolls about these things was still a thing

 

[Alexander1975]

The reason why i have my compass on the left side, is that i have my dive light on the right side. Like this i can easily illuminate my compass and check my heading even in low / zero light conditions

 

[lv2dive]

no i get it...
but i thought we were past the days where 6 pages of back and forth arguing with trolls about these things was still a thing

In all fairness I don't think VS is trolling but... By the same token, when a question has been asked and answered seven ways to Sunday I don't understand the need to keep asking it, looking for a different answer that makes more sense.

For me, a lot of the DIR/GUE principles didn't sit well at first. And that was AFTER I passed Fundies. I didn't buy into helium for dives in the 100-130 range (gasp, heresy!) and I sure as heck didn't think I needed nitrox for 30-60 foot dives. And nobody was going to tell me any different!!! But you know, no one tried to. We discussed the reasons for those things in class, and I listened with an open mind, and knew the choice was mine unless I was diving with other GUE people. So I didn't get all twisted about those "rules" that bugged me.

And then a funny thing happened along the way... I started to understand and internalize the advantages of the holistic approach, INCLUDING standard gases. And I pretty much don't see the need for air in a compressed state anymore, unless its a total PIA to get Nitrox. And I've figured out that deeper than 100' it's most definitely a good idea for me to have He in my tanks. In some cases, even shallower than 100'!

But no one gave me grief along the way. People knew how i felt and let me get there on my own; in the interim I respected the principles of standardization when diving with other GUE divers.

I guess what I am trying to day is that a lot of this does not translate on a message board. A good amount does, that's what piqued my interest in GUE in the first place. But only so much back and forth can occur in this dimension, and a class is really where it starts to make sense. And then, DIVING. And more diving. Maybe things will click, maybe they won't. But the best way to figure that out is to get experience with the system. By no means am I a stereotypical GUE diver, but I have grown into a strong believer of the core principles.

---------- Post added March 6th, 2014 at 12:37 PM ----------

It takes no time at all to unclip and reclip an SPG once you have done it a 100 or 10,000 times.

...With an AI unit you have:
- Easier, faster access to your pressure. No unclipping and re-clipping of the SPG necessary.

 

[LiteHedded]

you used to think i was crazy for diving 3030 at ginnie springs.

i dont wanna say I told you so, so I wont

 

[lv2dive]

as if you didn't just say it!!!! Lol

you used to think i was crazy for diving 3030 at ginnie springs.

i dont wanna say I told you so, so I wont

 

[Vegan Shark]

no i get it...
but i thought we were past the days where 6 pages of back and forth arguing with trolls about these things was still a thing

Calling me a troll is a bit unfair. I didn't walk in here saying, "DIR sucks!" or anything of the sort. I am quite DIR-curious, and plan on doing fundies and tech1 eventually. As I said before, a lot of things make sense to me. Having had an OAG experience where a traditional hose length was terrible, the 7' hose makes perfect sense. I also like the standard gasses, finning techniques, and a lot of the gear choices.

But when a system is so non-standard in the scuba community as a whole, of course people are going to have questions and argue.

Back to the issue of tables vs. computers:

- Standardization makes sense, but why not just have divers use computers with similar algorithm and conservatism factors if that's the concern?

- What is the research behind minimum decompression? Who says the minute stop and slide every 10 feet method is most efficient as preventing DCS? After reading that chapter, I looked at DAN articles that compared various research, and the most efficient ascent rates and safety stops were not the ones prescribed to by DIR, so is this method outdated?

- For sticking to a plan made ahead of time it works, but a lot of rec diving is go with the flow. Maybe you planned on following a sand bed at 40 ft for most of the dive, but when you get there you realize vis is bad, or see an interesting critter up shallower. So you go to 20 ft. Then you see something back down at 40, head there. Then you go to 30. Then you see interesting topography down at 60, so head down there. How can tables best computers for calculating see-saw profiles?

-Using a computer might teach reliance on the "magic bracelet" but how is this different than relying on the "magic tables"? One can mindlessly follow what a table tells them just as easily as they can a computer. Do not tech divers rely on the "magic program" like VPlanner?

I understand that tables and rules like 120 can and do work well. But it's not a question of what can work, it's a question of what works best. Doing math by hand can work fine, but it's slower and more error-prone than using a computer. In the same way, how can tables and in-head estimates trump a computer that accurately keeps tabs and optimizes all the data on the fly?

 

[MXGratefulDiver]

I understand that tables and rules like 120 can and do work well. But it's not a question of what can work, it's a question of what works best. Doing math by hand can work fine, but it's slower and more error-prone than using a computer. In the same way, how can tables and in-head estimates trump a computer that accurately keeps tabs and optimizes all the data on the fly?

I'll take a stab at that one ... not necessarily from the DIR perspective, but a common-sense one. For context, I do use a dive computer ... I own both a Liquivision X1 and a Shearwater Petrel and I fly them both in computer mode.

I do not, however, rely on the computer to dictate the profile of my dive. The reason is because the computer knows nothing about me. It doesn't know I'm 62 years old. It doesn't know I'm overweight. It doesn't know my overall fitness level, how much sleep I had last night, how much alcohol I've consumed in the past 24 hours, how well hydrated I am, or any number of other things about me that affect the contributing risks of DCS. Only I know those things. The dive computer follows a mathematical formula that is established by the manufacturer as "safe enough".

Now I believe that part of the reason why GUE doesn't want their divers using computers is because they want them to get in the habit of considering all those things I just mentioned ... and factor them into their dive profiles. Of course, if you follow the GUE regimen as intended, you're going to reduce or eliminate a lot of those factors based on overall fitness and health regimens. But the bottom line is that you learn how to factor those considerations into your dive plan only by doing them repetitively ... until they become ingrained habit.

When I wear my two computers side-by-side ... as I do whenever I'm doing overhead diving, whether physical or virtuall ... they will at various times during the dive display different numbers. Which one should I be listening to? Which one will give me the appropriate bottom time for the depth I'm diving ... or best reduce my risk of incurring DCS? The answer is neither or both ... depending on where in the dive I am at a given point in time. So the solution is to use them purely as "sanity checks" ... and rely on experience, rules of thumb, how I feel, and my own knowledge of what my limitations are when determining an appropriate ascent. This comes with practice. GUE is all about ingraining good habits, then following them through repetitive practice until they become ingrained.

That's not just a good GUE strategy, to my concern ... it's a good habit even if you don't (as I don't) buy into the holistic system that is GUE. It's about "thinking through" your dive. People who fly computers tend to rely on them too much to tell them how to control their dive. GUE wants you to be in control. If you can do that while flying a computer, great ... but in that case, you're not using the computer for its intended purpose, you're using it as just another data point for making your own decisions.

... Bob (Grateful Diver)