Will Air Integration in dive computers replace the SPG?

[CuzzA]

@Bennno, I agree location tracking is different. Definitely awesome though. I think it's Liquidvisions computer that has that feature. I don't know much about it, only read some marketing material.

I don't want to spin in circles, but set price aside and forget about yourself and think about recreational diving as a whole. Wouldn't you agree at least some of the planning part of WAI offers something to divers who don't dive all the time or simply got certified and that's it. Never learned much more than basic open water training? Would knowing your buddy's gas be a good thing? How about calculating ATR for both of you? Again, you may be an expert diver, but consider the training standards today and the majority of divers who have never heard rock bottom calculation. Remember, OOA is still the number one killer in diving, besides medical issues.

Also, remember no one is forcing anyone to buy it.

 

[guyharrisonphoto]

I was uncertain about the usefulness of the ATR option when I first got the computer (I basically only wanted the pressure readout on my wrist), so I decided to follow it on several dives to see how accurate it was. I found that, under a variey of dives in differing conditions, it was actually very accurate and I would surface within 100PSI of my pre-set reserve. So, once I found it was accurate under real-time, real-world dive conditions, I do, in fact, program an ending surface reserve and I do watch and pay attention to the ATR. And I do use all of the ATR because that is its purpose, to give you the maximum safe time at depth, and begin the ascent with sufficient gas including your set reserve. Diving to the ATR is not pushing "the edge" as someone above suggested, it is following the conservatism of your plan--which is initially determined by the reserve you set.

I also might deviate from the ATR if in my assessment the dive is exceptionally benign, or exceptionally challenging. It is information, pretty accurate and useful information, but not an "absolute." So, when is it really useful? When a dive starts easy but a current whips up, or when I bound around between 70 and 110 feet following photo subjects, or when I am still for a long time, then have a burst of activity--in other words, the myriad of situations that planning and estimating gas consumption with a paper cannot account precisely for.

Many divers I meet using AI do not test the algorithm like I did, and just program in the "500" because that is the universal, informal rule of thumb around where I dive. However, given what I now know, I cannot see how this is any thing other than a tremendous safety benefit for most rec divers. If they pay attention to what the computer is telling them they will make it to the surface with their reserve, and will probably also have enough gas to share if an emergency arises. Especially since gas management is not really taught in OW or AOW unless you have an exceptional instructor.

I don't know about Oceanic. My computer shows both NDL remaining, and ATR. They are separate functions, having no relationship to one another. ATR is ttime remaining based on your rate of gas consumption and has no tie to the deco calculation at all.

 

[Bennno]

@Lorenzoid
No, the computer maximizes your dive time by calculating you NDL in real-time, a table can't do that (that's the reason why almost everybody in rec diving uses a computer these days, there is an actual advantage). AI doesn't maximize dive time, you wouldn't cut into you 'rock bottom' or turn pressure would you? So it does not change your diving and that's why most people don't use it.

 

[Bennno]

Would knowing your buddy's gas be a good thing? How about calculating ATR for both of you?

Just ask your buddy how much gas he or she has left. I don't calculate ATR on a NDL dive I just go by pressure... whoever hits return pressure first signals the buddy and you swim back to the boat. Basic scuba training is all you need. If you have fun using it, that's fine. I'm not one of the people that says AI is dangerous, I just don't think it really helps you.

 

[CuzzA]

@guyharrisonphoto I haven't dove the computer enough to assess its accuracy. I imagine I may use it similar to you after some time.

Lets all not forget, no one is forcing anyone to use WAI.

I never thought this topic would generate such a response, but I've enjoyed reading all the contributions...

So will scooters replace fins in the future? Haha, I'm kidding please do not entertain that question.

 

[Lorenzoid]

@LorenzoidAI doesn't maximize dive time, you wouldn't cut into you 'rock bottom' or turn pressure would you? So it does not change your diving and that's why most people don't use it.

Two things. First, assuming you're doing a multi-level dive and will not be staying at one depth, as a practical matter you probably won't write down on a wrist slate or memorize more than a few different depths and their corresponding rock bottom pressures that you calculated before the dive. A computer could do the calculation on the fly, for any pressure. So you have greater granularity. Somewhat analogous to a computer giving you greater granularity calculating NDLs for a multi-level dive than you would have gotten if you were to use a table. Second, when we calculate rock bottom we choose some typically conservative SAC rates. A computer could use your real-time calculated SAC rates, and add some factor to account for increase in SAC rate due to handling the stressful OOA situation. Less air might be reserved for rock bottom than if you had done the traditional, manual calculation of rock bottom using some estimated SAC rates greater than your real-time calculated SAC rates. Who knows. Purely fantasizing, tossing out ideas about how rock bottom could be modified using real-time calculated SAC rates. And I'm absolutely NOT saying this is a GOOD idea.

 

[agilis]

This goes back to the idea that one doesn't need a computer to compute NDLs, either. You can use a table. For rock bottom, I use a slate on which I have written three or four depths and the corresponding "rock bottom" pressures I need to have in order for my buddy and I to ascend safely, taking into account increase in SAC due to stress, etc. But that is based on a conservative estimate of our SACs. A computer with WAI that monitors both divers in a team could use their real-time SACs to estimate rock bottom at the current depth. The real-time computation of SAC could be thought of as giving the diver "more air time" than if estimated manually, just as a computer can be thought of as giving the diver "more no-deco time" than if estimated manually (using a table). In the end, it's all about leveraging technology to maximize one's dive time. Achieving maximum dive time while taking no more decompression precautions than required to avoid the bends and while carrying no more air than required to avoid drowning is an important goal to some people, it seems. Some people prefer to get as close to the edge as possible. Others are okay with sacrificing dive time for safety margin.

Look Ma, no hands!

The goal of "achieving maximum dive time while taking no more decompression precautions than required to avoid the bends and while carrying no more air than required to avoid drowning" is intriguing. It reminds me of people who would let the lever pop from a grenade and then hold it for the maximum time possible.

In any case, decompression hits are frequently unearned, striking for reasons that can only be guessed at. I guess I'm an old fashioned old-timer who regards taking unnecessary risks as the hallmark of an idiot.
Sacrificing a significant safety margin to extend dive time is a concept so outrageously beyond my conception of rational behavior that it strikes me as infantile lunacy.

In the interests of full disclosure I must admit that I've done a number of stupid things while scuba diving. I wince when I recall how deep I've been on standard atmosphere, tanks filled by a oily rattletrap compressor at a third world hole in the wall shop. I remember that a single breath made the tanks ring faintly as Cecil and I gazed into a fathomless abyss from a ledge at the bottom of a sloping wall, too narked to fully appreciate what we were experiencing.

The maximum depth needle on my depth gauge later revealed the extent of my folly.

 

[Lorenzoid]

I wonder if people who are keen on the idea that the ATR feature (or some smarter future incarnation thereof) might help economize their air supply usage are the same people who seek out "the most liberal" computer (so they have the option of economizing decompression). I guess I'm just a wasteful diver. I often am back at the boat with plenty of no-deco time and gas left.

 

[AJ]

Correct, but by that logic what is the point of having an ascent rate alarm, or a planned depth alarm? Or, for that matter, an NDL readout? You can track all of those without a computer too.

True, there is no point in having them. I don't use them.

 

[scubadada]

Excuse the dive computer n0ob question. Do the Oceanic DC's dynamically display the lower number it calculates between ATR & DTR? Shouldn't the DTR always be lower since it takes the ATR then also adjusts down (safer or more cushion) for oxygen/nitrogen absorption? Is this user settable? I have the Aeris A300 but am just starting to play around with it. Yes I have the PDF manual, in the middle of reading it.

Either ATR or NDL will be shown on the primary screen, whichever is controlling DTR. The other parameter is shown on the alternate screen. This is not user definable. When ATR is shown on my VT3, I often just glance over at my Geo2 backup to check NDL, rather than accessing the alternate screen