Will Air Integration in dive computers replace the SPG?

[CuzzA]

I agree, at the end of the day, it falls on the diver to recognize issues or situations that appear suspect. The problem is many are focused on the fact they are actually diving. The visual overload of being in the environment, so they rely on an instrument to tell them when it's time to get out of that environment.

Perhaps all of this falls on training standards. Based on a lot of what I've read on SB, today's open water certification class is nothing compared to what it used to be. I don't have a problem with setting the tables aside for the dive computer (although I think they should be introduced and provided to the student. I had to search and learn them on my own); however, IIRC, today's basic training does not go into "detail" about time and gas management, especially without the assistance of an instrument. Figuring out your sac/rmv rate, rock bottom calculations, understanding how that correlates to your gas, depth and time are not a focus of open water basic training. Basically the protocol is, if something fails, end the dive. Unfortunately a stuck needle doesn't necessarily indicate failure to the operator. So what we are left with is thousands of divers who rely on their instruments.

I can do a AI failure poll too, but I would want to identify when, if any, technology improvements were made and clarify that. It's my understanding the SPG has been unchanged for ~40 years, but the tech in AI may have had some breakthrough improvement which would have to be taken into consideration. A failure of the first AI ~20 years ago may not represent the same tech today.

 

[Lorenzoid]

I like seeing a needle move, observe how it responds to variables like depth and activity level. It involves the observer in the same way that an analog watch or oil pressure gauge does.

I do, too, but the WAI fans here will point out that a needle (or bar graph or anything else that satisfies our analog brains) can be depicted on an electronic display.

EDIT: Whoops, I didn't read the several posts after this pointing the same thing out. Still getting used to the new board format.

 

[AJ]

Perhaps all of this falls on training standards. Based on a lot of what I've read on SB, today's open water certification class is nothing compared to what it used to be. I don't have a problem with setting the tables aside for the dive computer (although I think they should be introduced and provided to the student. I had to search and learn them on my own); however, IIRC, today's basic training does not go into "detail" about time and gas management, especially without the assistance of an instrument. Figuring out your sac/rmv rate, rock bottom calculations, understanding how that correlates to your gas, depth and time are not a focus of open water basic training. Basically the protocol is, if something fails, end the dive. Unfortunately a stuck needle doesn't necessarily indicate failure to the operator. So what we are left with is thousands of divers who rely on their instruments.

Agree. Training is far more important than tools. But on the other hand: if tools help to prevent accidents from happening, it does not matter what tool is used. I do not oppose or promote AI or SPG. It bothers me a litle that the safety argument is used so wrongully in this discussion imo. It's not about safety, it's about personal choice and that's fine.

To me it's simple: use what you like. I like SPG for now because it is cheap and reliable. I do not use AI (anymore) based on my bad experience with my Suunto D4i. However, if SW decides to offer AI I will look into it. No doubt about that. I trust SW to deliver something good. I'am not religiuos about AI or not, just want a tool that does what it is supposed to do for a reasonable price.

About statistics: I just have to point to both films from Al Gore and Michael Moore about the climate problem. They are the perfect example of how statistics can be used to tell "the truth". Statistics don't lie, they just don't mean anything unless you believe them. So don't bother finding statistics on AI, they won't add to this discussion

 

[stuartv]

That's not SPG failure, that's diver failure.

That is Baloney, with a capital B. It's SPG AND diver failure. And since we're talking about SPG vs AI, the diver would be a constant and therefore not a factor in deciding between the two. There's the poll and there seems to be lots of anecdotal evidence that SPGs are not especially reliable. My mechanical SPG blew an O-ring on its spool in the first 10 dives. My WAI has been 100% reliable over 70 dives, so far. For some reason, it just seems like when we talk about SPGs not being reliable, it's accepted as okay and dismissed because "it's sad to think a diver would be killed because of some minor failure... Never ever trust your instruments, be a thinking diver!" But, when we talk about WAI being unreliable (though it appears to be more reliable than mechanical SPGs), suddenly that is a reason to never even use them. "The battery has to be replaced once a year. That is unacceptable and it shouldn't be used!" Well, at least if you do the maintenance on WAI, it's not going to tell you you have 500 psi left when you're actually running out.

...

Those of you who keep insisting on accusing "the other side" of NEEDING AI are disingenuous and not helping the discussion at all. Nobody that I've seen has said they NEED it. They have said they like the increased convenience and additional information they get.

Also, I don't dive AL80s - well, almost never. So, even if my SAC worked out to 1.0 on an AL80, that is irrelevant to how convenient and easy the arithmetic would be (for me, anyway). Not to mention that I live and mostly dive in the U.S. where the "standard" is Imperial measurements and I bought my gear (i.e. my mechanical SPGs) based on what my instructors recommended, which is Imperial. So, the baloney about "if you can't multiply by 1, you shouldn't be diving" (paraphrasing just a tiny bit) is, again, just that - baloney, and not an honest and sincere effort to engage in useful discussion.

Batteries: My transmitter is over a year old and still on the original battery, which still reports as "Good" on my computer. It takes one CR2 battery. The battery is simply a non-issue for anyone except a person who is just looking for any possible excuse to knock WAI. Really? The environmental impact of making and then throwing away 1 CR2 battery per year (or less)? Go out to your street on trash day and look at what all your neighbors are throwing out, then get back to me on the evils of manufacturing and disposing of 1 CR2 a year.

 

[Bennno]

When do you going to give an example for what kind of 'mental arithmetic' you have to do without the AI? Stuart?

If something is baloney here, it's that you have to calculate anything while doing a rec dive. This argument is a red herring, so is this 'getting distracted' argument. If you're not checking your gauges regularly or you don't notice that your needle got stuck it means you are sloppy diver or that you have not been properly trained or both, that's all, has nothing to do with the gear you're using whatsoever.

BTW: I love it when people that have been diving for a couple of years go online to lecture instructors on gear issues.

Get over it guys, have fun with your toys, nobody said toys are a bad thing. Porsches and motorbikes are toys to... do they make sense? No. Do you need them? No.
If you wanna pay extra money for shiny toys with extra LED light, have fun.

The vast majority of people that do advanced dives such as deco, cave and even rebreathers don't use AI... I guess all these people must be all idiots.

 

[AJ]

That is Baloney, with a capital B.

Well, that's your opnion. Equipment failure should not lead to accidents. If it does, it's diver failure imo, no excuses.

It's SPG AND diver failure. And since we're talking about SPG vs AI, the diver would be a constant and therefore not a factor in deciding between the two.

Well, that is baloney with a capital B. But I rest my case as in your opinion instruments seem to be more important than brains. I see no point in further arguing as we won't reach common ground here.

 

[dmaziuk]

Of course the needle drops more rapidly, all other things being equal, in a smaller tank. That's a given, glaringly obvious, not requiring any thought other than the obvious understanding that a 80 cf tank will move the needle at approximately half the rate of a 40cf tank, and the diminishing time element will be more precipitous with the smaller tank.

A different SPG? Are you really serious?The reasoning involved in this concept completely eludes me.

Simple: if you're watching the rate of change on a slim SPG and your tanks are huge, the needle hardly moves at all and you can't see s*it.

 

[stuartv]

When do you going to give an example for what kind of 'mental arithmetic' you have to do without the AI? Stuart?

Already did. Very explicitly.

Well, that's your opnion. Equipment failure should not lead to accidents.

You said before that it was not an equipment failure. I said that's baloney. Now you are saying that it is an equipment failure (but should not lead to an accident). Well, which is it?

I said that it is an SPG AND a diver failure. That means that I said that it's an SPG failure and it is also a failure on the diver's part. You said that my statement is baloney. As you already said that it's not an equipment failure, it's a diver failure, you have made it very clear that you believe an SPG that reads 500 psi when you are actually empty is not an equipment failure.

An SPG that gives a reading that is inaccurate (by more than the accepted tolerance) IS an equipment failure (okay, to me and any competent mechanical engineer) and it surprises me that even the most vehement anti-AI person would try to deny that. But, I guess it does explain how you can stick to your guns on mechanical SPGs being more reliable than a WAI transmitter...

 

[Lorenzoid]

What would be most "convenient" to me would be to not have to monitor my air at all, and to have as little information presented to me as possible while still enabling me to dive safely. Can they please invent something that does that? I have no idea what it would be like--it's sort of a fanciful or futuristic idea--but that would really be my ultimate goal, whatever it may entail. Diving safely while free from as much "information" as possible.

 

[boulderjohn]

I used to think I did righteous safety stops until my Cobra showed all I did was safety pauses. It was a great tool for analysis. I'm way past the Cobra, but I've learned a lot about my diving from my PDC.

This quote got me thinking about my early diving days. My first computer (1999) was a Cobra, and I liked the AI feature a lot. Looking back at those days through my experience as an educator, I realize that its most valuable feature was its ability to teach me about air usage. This is the opposite of what I suspect most people think, so let me explain.

Every time I looked at the computer, it told me how much air time I had if I continued at that depth and that rate of activity. As I changed depths and rates of activity, I could see it change. Whether I was trying to learn anything or not, I naturally developed over time an intuitive sense of those changes. I played with it. If I did not like that prediction, I would change my dive in some way. Depth. Activity. Breathing patterns. I learned when I had to ascend to maintain a gas reserve. The near instant feedback to what I was doing was a valuable educational tool. Without trying, I was truly learning gas management while I dived.

Eventually, I developed that sense to the degree that I didn't need the AI any more. I stopped paying attention to it. Everything was now intuitive.

Then I got into technical diving, and it was a different world. Now everything was pre-planned to a degree I had not thought possible. I went into each dive knowing how much gas I needed for each phase, and I carried way more than I was expected to need. I learned to check an SPG only occasionally to make sure everything was going according to plan. I no longer had a need to see those numbers on a nearly continuous basis.

I have not used AI for many years now. I am not particularly set against it, but I just don't feel like I need it. On the other hand, I really do think that in my earlier days of diving it was very helpful to me, and I think I learned a lot from using it.