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

[fnog]

Hi everyone,

I would like to bluntly ask the title question, as I am a rec diver with little experience. The stickies and various posts hint at some rationale behind the refusal of Shearwater, OSTC, xDeep, Liquivision and other tech brands to produce DCs with AI -by AI, I do not mean dying blond hair black-. Why would all your gas tank pressures not be recorded by the DC ? Given the price tag of these brands I guess it would make little difference to add gas integration hardware (for the software part, I have no clue).

I guess that _relying_ on a DC with wireless pressure gauge for your remaining gas is not safe, compared to reading analog gauges. But there are probably a number of solutions to this:
- sell only transmitters that are attached to an analog (mechanical) SPG
- have some analog means of indicating on the SPG that the transmitter battery is low/dead
- no display of gas pressures on the primary screen of the DC in default layout (so that it remains easier to stay safe, grab the SPG and look rather than push buttons on the DC).

My first impression is that the info of breathing rate in the log is valuable. Don't you want to know and learn from your logs how you have reacted to some events like cold, worries, surge on a cliff, cramps, task load, overuse of lungs to adapt to sudden depth/buoyancy change... in terms of ventilation ?

I have already noticed that my console DC is "smoothing" pressure readings and that it is impossible to notice that a valve is not properly open all-the-way; and that it takes too long until the DC wakes up and gives a stable reading during the first surface gas check. But this could be partly fixed in software if I had access (OSTC).

As a side remark, I find that the wireless capabilities of both high end or massmarket DCs are disappointing if compared to all the dirt cheap electronic gizmos. One would expect at the very least some positioning info on buddy (distance, depth diff), using a standard protocol so that it works even if buddy has brand XYZ, and the adoption of bluetooth and usual NFC technologies for linking with PCs & phones.

Anyhow, I would mostly like to read the reasons behind lack of AI, from those who know why they do not want it in their DC.
TIA.

 

[tomfcrist]

As far as a dive computer used for tech diving, you have already noticed that analog SPGs are probably more bulletproof than AI. You also have to consider that AI transmitters have a tendancy to fail, and if you dont have an anolog backup, you are diving blind. Some Tech divers choose to use a high end deco computer, and have a wireless AI computer as their backup. This allows them to have digital access to their backgas pressure, while still having an analog guage. The biggest problem with AI in my opinion is that tech divers carry multiple gasses. Backgas, Deco gas, and sometimes More deco gas. Imagine having a decompression computer that has to be wirelessly connected to 4 different gas sources and having to differentiate between each one. It is more foolproof to use analog in this scenario, not to mention a hell of a lot cheaper and more reliable.

 

[flots am]

Hi everyone,

I would like to bluntly ask the title question, as I am a rec diver with little experience. The stickies and various posts hint at some rationale behind the refusal of Shearwater, OSTC, xDeep, Liquivision and other tech brands to produce DCs with AI -by AI, I do not mean dying blond hair black-. Why
TIA.

Uwatec computer are AI.

My best guess is that wireless represents an additional expense that the small manufacturers are unwilling to tackle. You have to realize that SCUBA is a niche market and within that niche, tech divers who buy expensive computers are just a tiny slice and within that niche, tech dives who want AI is an even tinier slice.

There really isn't a lot of market there.

Also, most tech divers dive with an SPG and don't use their computer for gas measurements. Many don't use their computer as a computer. I have a Galileo, for example, that it supposedly fully capable of handling an entire deco dive, start to finish including gas switches, however I do not trust it with my life. On an overhead dive, my "computer" is a wrist slate with a laser-printed vPlanner plan taped to it with clear packing tape.

A dead computer is something that just can't happen when you're using paper. this is especially important in cases where a dead computer could mean "dead you".

flots.

 

[Stoo]

I can't offer any reason, other than to say that I've always though that AI was a great solution to a problem that didn't exist. An SPG is a remarkably simple, accurate and pretty-much fool-proof way of monitoring gas supply. In tech diving, some combination of experience and training mean that most divers already "know" (in that the consumption has been calculated in advance) what their tank pressure will be and checking the SPG is something of a formality and confirmation.

I've never used an air-integrated computer, and none of my buddies use them, so this is probably a stupid question, but if someone is using an AI computer, do they eliminate the SPG altogether? If not, then the AI is really just "fluff". If they do, then that strikes me as relying on a bit of wireless technology for some pretty critical information.

 

[fnog]

Tom,
I understand that AI as it is today is not as reliable as analog SPGs, and that it may not even be considered as a valid redundancy. And that things are safer when kept simple. It is indeed complicated to label your SPGs and declare them to the DC when you have many.

On this topic of reliability, I am no expert, but just under the impression that hardware developpers (especially those from Shearwater and the likes) could very well design a passive and reliable HP wireless gauge. One that works the same way as your office badge: no batteries needed as long as you are close enough to a powered receiver (the DC). If such a transmitter was included in the otherwise usual analog SPG (i.e. no extra housing/plumbing costs), the savings can be used for redundant piezo sensors and xmit electronics, to make 100% failure very unlikely.

Budget grows indeed a bit with the number of tanks, deco, ponies etc,... but how much of a fraction is that, compared to analyser cells, O2 regulators, boosters and other such expensive tech and trimix gear ?
Then again, is it not valuable to see in the logs the exact correlation between the moment of gas (tank) switches and other data like ascent/breathing rate ?

 

[Lorenzoid]

AI would add another failure point. If you keep two systems separate and one fails, the failure of one cannot affect the other. In this instance, if the computer fails, the computer failure does not affect your ability to read your SPG. The analog SPG is such a simple mechanism that it is hugely unlikely to fail. I have no tech training, but I do see the logic of keeping gas readings and bottom time calculations separate. And not only separate, but as simple and therefore less prone to failure as possible.

 

[nimoh]

Tom,
I understand that AI as it is today is not as reliable as analog SPGs, and that it may not even be considered as a valid redundancy. And that things are safer when kept simple. It is indeed complicated to label your SPGs and declare them to the DC when you have many.

On this topic of reliability, I am no expert, but just under the impression that hardware developpers (especially those from Shearwater and the likes) could very well design a passive and reliable HP wireless gauge. One that works the same way as your office badge: no batteries needed as long as you are close enough to a powered receiver (the DC). If such a transmitter was included in the otherwise usual analog SPG (i.e. no extra housing/plumbing costs), the savings can be used for redundant piezo sensors and xmit electronics, to make 100% failure very unlikely.

Budget grows indeed a bit with the number of tanks, deco, ponies etc,... but how much of a fraction is that, compared to analyser cells, O2 regulators, boosters and other such expensive tech and trimix gear ?
Then again, is it not valuable to see in the logs the exact correlation between the moment of gas (tank) switches and other data like ascent/breathing rate ?

I think the short answer is that AI is unnecessary and so it is difficult to justify the expense. Boosters are also unnecessary as you can fill your tanks at a dive shop, and as such most tec divers don't own boosters.

Analyzers are also somewhat unnecessary as you can analyze at the shop using their analyzer, although I'm guessing most tec divers own analyzers for the convenience of analyzing at the dive site. For me personally, I commonly partial pressure blend trimix the morning of a dive and use the vibration of driving to the dive site to mix the tank well before analyzing, so in that respect an analyzer is necessary, although I could fill tanks a few days in advance.

As for logging tank pressures, you can do that with an analog gauge as well. I generally write down starting pressures and ending pressures along side my dive plan in my wetnotes.

 

[victor]

I don't see that the range of badge type technology would work, thats normally only a couple of inches at best.
All pairings would need to be done in a radio quiet zone to ensure that you did not pair with your buddies, or some other divers first stage.
Then there might be the question if you hand off a bottle to your buddy due to some gas issue, no SPG so no way to trak the preasure.
I can understand the attraction, you could keep track of the mix and preasure of multiple tanks allowing you to set alarms if a wrong gas is selected on a gas switch or the preasure in a tank is dropping when it is not selected. From a programming perspective all very interesting.
However the issues is when something goes wrong, and it will, and the IT may hide that it is going wrong, and worse there may be no backup.
Think of it in the same way as removing the pilot from planes. Technically no issue, George can take off, fly to your destination and land.
Would you fly without a pilot?

 

[GrumpyOldGuy]

Planning is also a difference IMHO. The way most AI computers get used is reactive, it calculates the time you have at the current depth less a calculated allowance for a normal ascent (open water). Its pretty simple and does work for most OW divers.

Advanced divers don't follow what is "normal", it may be in an overhead (actual or virtual) and have complex dive plans with multiple depths, multiple air sources and more complex dive plans. Adding this to a dive computer requires a complex user interface, like programming an old style VCR x 10, most people won't learn to do it right / reliably. There is no replacing a manual gas plan where you become intimately familiar with the process and the nuances involved, once you do that the value of the AI is decreased.

 

[nimoh]

There is no replacing a manual gas plan where you become intimately familiar with the process and the nuances involved, once you do that the value of the AI is decreased.

I agree and will add that on less complicated dives it is good practice to dive in the same manner in order to maintain that familiarity.