No air integration in high-end and tech DCs . Why ?

[Diver0001]

Yeah, I guess that's one way to plan it. I don't dive in caves though so I tend to plan my dive more based on how much deco I want to do.

Good point though. You really should get an AI computer, John. That way you don't need to check your gas, it will blink at you

R..

 

[eelnoraa]

I would like to thank everyone for the honest attempts to answer the original question.

To those who would like me to shut up and, instead of asking scuba questions on a scuba forum, go and design that hypothetical tec DC, I would like to say: sure why not. I just love to spend my life in design of useless and potentially dangerous equipment. Since my pal Lex L. is a bit broke lately, and I am a bit slow in the head from smoking Zissou's ciggies, just send me the numbers for the national lottery and the formula for the elixir of youth, and I will do it. :joke:

Some people seem to know that it is impossible to make a purely passive beacon, from their knowledge in radio and electronics, but do not want to give details and numbers in this forum. I understand: this is a bit offtopic, even though a forum on DCs will automaticly to be a bit technical (in the engineering sense). If you have a minute, I would appreciate that you PM this however. One can easily find articles like "A self-sustaining, autonomous, wireless-sensor beacon powered from long-range, ambient, RF energy ", but these indeed relate to transmission in air, not salty water, and to a strong RF power source, not a DC running on 10 grams of battery. How about ultrasound instead of RF ? Could that both transmit enough power and receive data ? Still, it appears simpler to use a fiber casing on the SPG with a few turns of non oxydisable loop antenna and capacitor on the inside. That would be decently sturdy and has no obvious reason to disturb the operation of the SPG (exploding capacitor ? oxyde reaching mechanical parts ?).

That two systems have to be totally separate to reduce risks is not convincing. The failure probability of separate systems that are correlated (for example: you bought your cells at the same time from the same provider) is not zero. Let me restate that: if you want to believe that it is zero so you can dive quietly and safely, than it IS zero. Freedom of opinion and all that...If those two systems have components with high risks, I believe that is better that both systems have access to that component. What if the O2 sensor on one circuit is gone, and the other has a battery problem or an electrical open circuit ? You wish you had wired all O2 cells to both systems then. The extra wiring compared to the separate systems situation does not add failure risks, it just reduces them. (Again: a hypothetical question. I have never approached a rebreather, mostly to avoid being bitten by the owners).

The discussion has advanced quite a bit since yesterday, so I would like to remind everyone that I am a rec diver with about 60 logged dives. My job and certifications outside of scuba are probably of little interest here. My question was only a naive attempt at undertanding the dive computers market and evolution, and I am quite satisfied with the answers so far. I am not here to question the principles of an activity that I do not even know, less to lecture anyone. I am just hoping for a thorough and rational answer. If you believe my question is absurd, I am ready to take it. Just explain why.

So far the best answer in my eyes has been summed up by J. Lapenta (even if he publicly accused me of raping the principal): minimalism and conservatism are in the principles. Because AI is not needed for safety or to perform anything essential to the dive, it is rejected as an extra distraction and failure point. Relying on the DC in itself is dubious and it is better to have tables with backups and redundant bottom timers. (correct me if I misunderstood that)

An other answer is that tec divers know their gas volume per minute rate under various conditions and have integrated in their guts a feel for their remaining gas, such that they need the SPG not for information but just for confirmation. That is less valid. They integrated that skill using tools (tablet, timer, SPG, depth gauge, arithmetics) and experience. Add another tool to the mix and those who learn tec may have it better and faster.

There is also a principle to electronics integration and it need not clash with those of tec diving. Could some of you then imagine, and accept after years or field usage by rec divers, using a bottom timer that has inside properly designed electronics for doing AI on all your tanks for 100$ extra, but simply use firmware that completely ignores those sensors ? It is a solution to reconcile both principles, but it does not promote an improvement of the quality and openness standards of mass market DCs by adopting features from tec. The rule of this game seems to be that features are introduced first with low quality in mass market DCs, and then much later adopted and maybe improved in quality and safety by niche tec equipment makers who will make expensive models, while the mass DCs are not improved in quality and left with version 0.2 of the feature. If that satisfies everyone, I will be just fine with that too.

Even in air, passive beacon is one thing, but a "beacon" that is capable of sensing pressure of a tank, then digitized the signal and send it off is another thing. To do that, you need some power. Approximately power transmission by magnetic field is possible (tooth brush and cell phone), but range and and amount of power is very limited. The coil need to to response to this megnatic field also needs to be quite big. Electro-magnetic wave transmission in water is very inefficently.

Ultra sonic as known in ultra sonic clean type of signal require physical movement, which consume even more power. I haven't seen or known anything that can beacon an ultra sonic signal passively. Lynx uses similar technology, sonar, it needs power in transmitter. Sonar is a low frequency signal which travel must more efficient in water. But lower frequency also mean bigger antenna, thus the size of the transmitter increase.

I mean with enough thinking, one can get a technology to work. But again, it is all about what advantage AI brings to the table vs potential risk associated with it. All I can't see what AI is doing for me besides consumption logging. This is even for rec diving. It is not something I am willing to get with any additional risk

 

[fnog]

So with all of the *relevant* information your computer has to display, why would you want to have the screen cluttered with information that you don't need and probably already know?

R..

Indeed why would I want that ? I don t. The original question is about AI for the purpose of debriefing/post dive usage of this data on a PC, in a place where you are maybe less narced or exposed to fatal risks. And I do not "want" it; that would be impossible since I am not a tec diver.

Aside from rate of breathing, this data can be used for example to correlate gas switches to any other parameter that is in the log. In a further post I acknowleged that this data is seen as useless by those tec divers who answered, and went on to ask if having the hardware present in the chip but powered off would be a problem. This may sound like a weird question but it is not regarding micro-electronics. The chips we use everyday are crammed with such unused features that are made for full coverage of a broader market as it makes economical sense. It can also improve reliability, but that is not a given.

If the usual log software like subsurface can not give continous RoB info already, it is easy to add it or get a workaround.

I perfectly accepted that this hypothetical feature is seen as useless by fully trained tec divers, but as a general rule I do not take without further debate answers that are not giving specific reasons. "I do not want it" or "The market does not exist" or "I am a specialist and sure it it impossible" or "Everything is the way it should be, do not bother" are rather vague answers to me. OK, this can be upsetting. I heard those clear, however, do not ignore them, and apologise to those who found it offensive that I kept asking for specifics, and also to those who found this question so absurd that it pollutes the forum.

 

[eelnoraa]

.... In a further post I acknowleged that this data is seen as useless by those tec divers who answered,

For most dives, not useless, but in very low priority compared to other aspects. If this data come for free of any risk, I think everyone is happy to take it. But if that comes with any potential risk, then I will choose not to take it.

I guess if there is a tec dive, where the goal is to study physiology or breather pattern and consumption rate under water, then divers conducting this dive will use a devices for this because it serves a meaningful purpose.

 

[hroark2112]

Maybe this will help....

Most gas switches are not done because the diver reached "X" psi in the tank. The gas switches are based on reaching certain depth and then breathing the specific gas for a period of time determined by the deco schedule, again totally not dependent on tank pressure. Tank pressure, with the obvious exception of turn pressure in overhead/cave diving, simply isn't a determining factor in executing the dive. Gas switches and deco stops & depths are determined by the deco schedule for the planned dive and the MOD of the gas being breathed.

 

[boulderjohn]

I perfectly accepted that this hypothetical feature is seen as useless by fully trained tec divers, but as a general rule I do not take without further debate answers that are not giving specific reasons. "I do not want it" or "The market does not exist" or "I am a specialist and sure it it impossible" or "Everything is the way it should be, do not bother" are rather vague answers to me. OK, this can be upsetting. I heard those clear, however, do not ignore them, and apologise to those who found it offensive that I kept asking for specifics, and also to those who found this question so absurd that it pollutes the forum.

Maybe you didn't notice it, but pretty much everybody who said "I don't want it" also explained why it was not wanted. The people who said "The market does not exist" are taking note of the number of people, both in this thread and in their daily lives, who say "I don't want it," and they are drawing a logical conclusion. You seem to be blind to those responses. I am guessing that if you are a computer manufacturer trying to gauge whether or not a market exists for launching an expensive project, a large number of people saying "I do not want it" (along with the reasons why it is not wanted) would be perceived as a pretty specific response. I assume from what you have been writing that if you were on the management team of such a company, you would be urging the project on, but a lot of other people at the table would be more wary.

I am frankly baffled by your continued thoughts in this thread. It seems to me that this is what you have said so far:

"I am a relatively new diver with no technical diving experience whatsoever. I asked experienced technical divers why they are not interested in a certain feature, and I see that they seem to be 100% opposed to its use. I do not have anything close to the experience and training that they do, but they are obviously wrong. I see it as my mission to give them the education they are clearly lacking."

 

[Diver0001]

Indeed why would I want that ? I don t. The original question is about AI for the purpose of debriefing/post dive usage of this data on a PC, in a place where you are maybe less narced or exposed to fatal risks. And I do not "want" it; that would be impossible since I am not a tec diver.

so.... you feel some (odd) need to analyze irrelevant data after the fact?

The data really IS irrelevant. The fact is this. Tek divers already know their SAC. Period.

Nothing you could analyze could result in the diver learning more about his/her air consumption than they already knew.

 

[boulderjohn]

Here is just a little more information for you that may help you understand the marketing situation.

1. The overall diving market is not huge to begin with. Only a small percentage of the world's population dives. Compare that to the automotive industry to see the difference.

2. Technical divers comprise a tiny, tiny percentage of the overall dive population.

3. Technical divers who use computers are a small subset of the small subset of technical divers. At least two technical diving instructional agencies do not teach the use of any computers whatsoever, whether they are AI or not. A large percentage of the divers and instructors in other agencies, possibly the majority, use decompression software on a computer or smart phone to create profiles for their dives. They then follow that plan using a simple bottom timer or a computer in gauge mode.

4. Of the technical divers who do use technical computers, a large percentage of them plan and execute their dives using software-derived programs, using their computers as backups in case something goes wrong with their planned dives.

5. Of the remaining divers, a portion will use computers as has been described by some in this thread, feeling that an AI feature is unnecessary.

6. What remains is your target market.

 

[eelnoraa]

Limited market is definitely the case here as well. What is the percentage of people is a diver? Out of them, what is the percentage of tec diver? The amount of resource to mature such a product probably far out weight the financial gain.

As with all other consumer based technology, the advancement is really based on market or protential market. TV, mobile devices ... as they advance and people adopte. Billion of people are buying them every 2 years if not sooner. Dive computer, especially tech dive computer is different story. No matter how much it advances, the market really doesn't change much. No financial sense to put in a lot of resource. But I am not ruling out anything. It could happen one day, just I won't hold my breath

 

[drrich2]

Been following this thread with interest. I've historically been curious as to why some tec. divers not only didn't want AI, but at times a minority seemed contemptuous or hostile to the idea (I'm speaking of my impression from other threads; this one has actually been fairly objective in the discussion). I have no tec. training and like my computer auto-logging my start/end pressures for later download and desktop computer logging, so I figured some tec. people would, too.

The discussions in this thread have been helpful at gaining insight into why many tec. divers don't want it. People routinely using multiple bottles who don't want to bother trying to tell the computer every time they switch is understandable, for example.

All this makes sense if we're talking about tec. exclusive dive computers.

But there's another potential niche. I've seen fairly new rec. divers ask about what computer to buy, and the Petrel suggested on the grounds it's a great computer and you can 'grow into it' if you ever go tec. Some of us then say 'AI is nice and the Petrel can't do that.' And off we go, given that only a small minority of rec. divers ever go into tec. diving (wonder what %?). And the recent inclusion of a recreational mode in the Petrel, if I recall correctly, would suggest that Shearwater is aware their product could appeal to a broader market (rec. + tec., not just tec.).

This could shift focus off tec., bad for the tec. community, or greatly raise revenues, funding more R&D, good for tec.

My point: while Shearwater might not add AI to the Petrel for tec. divers, it might want to add the capability in order to sell more Petrels to rec. divers, and so the tec. people might get the capability in theirs, which they would be free not to use, and if purchased without a transmitter likely with minimal added cost. The only downside then seems to be the perceived small increase in failure risk of having a more complex computer; 'more to go wrong.'

So, if Shearwater decides they'd like a bigger bite of the rec. market pie, should they add AI to the Petrel (which tec. divers could disable and not buy transmitters for), or should they make a different model for the rec. market? Imagine the market confusion if the rec. version could do everything the tec. version could, plus AI.

Richard.