Will Air Integration in dive computers replace the SPG?

[DevonDiver]

Or, you could just put a transmitter on the right post of your backmount doubles and use it as an SPG. If nothing goes wrong, it's more convenient to check your pressure. If you end up shutting down the left post for some reason, then you still have an SPG.

So, now, it's again being suggested that technical divers should have redundancy of SPG/AI, increasing failure points for absolutely no necessary benefit.

Thus breaking a cardinal principle of technical diving, for the sake of convenience.

This has been explained repeatedly. No offense intended, but this is indicative of the, very real, mindset transition between rec and tec. It's what is taught to every technical diving student. Learn technical diving and you will understand.

You know, in case you have WAI for Rec diving anyway and you want to use it on your Tech rig, too.

Along with your split fins, poke stick, suicide clips, retractors and etch-a-sketch slates?

And leave mechanical SPGs on all your other cylinders.

As a technical diver... the critical issue with gas is DECOMPRESSION. You do understand that we are obligated to complete decompression right? Or we get really, really sick.

So... when considering any possible benefit for AI in technical diving - the first and foremost concern is whether we have enough deco gas to fulfill our obligation.

We can abort a dive at any time...and (unless vast quantity of gas is lost) make our ascent from the bottom. What matters is whether we have enough deco gas.

 

[The Chairman]

So... when considering any possible benefit for AI in technical diving

Then it would probably be best to post this in the Tech forum and not the Basic forum. We get that you don't want to innovate, but not everyone is a Luddite. A lot of people, including tech divers, want to improve how things are done. You seem to want to do it the same way regardless of the advancements and block the advancement in the name of "Cardinal Rules" that were of course, lest anyone dare to think on their own, "written in blood".

 

[CuzzA]

I'm surprised a manufacturer would design a circuit so badly. A single diode would completely solve that problem and probably would cost less than printing the warning label.

Honestly I do not know how it is built. I don't know if it's an idiot warning that if you put the battery in wrong it's not going to work, thus eliminating a few customer service calls or if it in fact could damage the TX and is poorly designed.

But, it flat out warns not to put the battery in the wrong way, so I'm not going to experiment to find out.

 

[CuzzA]

Yes, and a four diode bridge would mean the battery could go in in either direction as long as you can tolerate the drop in voltage due to the diodes.
Totally agree.

A tank of compressed gas contains an awesome amount of energy, Waaaaay too much to use to its full capacity. The tiniest bit of this could be used to keep resupplying a battery on every breath. I could see a tiny spinner consisting of rare earth magnets that are driven by tank pressure gas as it just enters the primary reg. The spinner jams, no prob. HP gas just flows around it. Now, you don't need to use fancy ass high-energy batteries, you can back down to the good old proven reliable types. Just like the alternator in your car working with a box of sulfuric acid and lead, or the space station.

So who will be the first regulator manufacturer to offer a high pressure port with a stable control voltage as an equipment option?

It's interesting. You're right though, there's a ton of energy right on your back, just need a way to harness it for use. I could imagine a complete energy pack installed on the first stage to power multiple tools like your WAI transmitter or perhaps even a dive light. Maybe even a scooter if you could harness enough energy. Basically a high pressure alternator.

Starting to look more like the "Imperial System."

 

[AJ]

We get that you don't want to innovate, but not everyone is a Luddite. A lot of people, including tech divers, want to improve how things are done.

What's the innovation going from SPG to AI? Results are the same, just another way of doing things? So I wonder, why are you insisting on AI as the future solution and improvement to SPG? No pun intended, I'am just wondering because after after all these posts in this thread I still have'nt read the real killer feature AI is supposed to have. A lot of personal reasons why AI is better (or worse for that matter), but no objective description of the real killer feature AI is supposed to have and why we should all use it. Please enlighten me about this one feature.

 

[CuzzA]

What's the innovation going from SPG to AI? Results are the same, just another way of doing things? So I wonder, why are you insisting on AI as the future solution and improvement to SPG? No pun intended, I'am just wondering because after after all these posts in this thread I still have'nt read the real killer feature AI is supposed to have. A lot of personal reasons why AI is better (or worse for that matter), but no objective description of the real killer feature AI is supposed to have and why we should all use it. Please enlighten me about this one feature.

Simple, no hose.

 

[packrat12]

So, basically, you didn't use to plan your dives. And you think that way of diving applies to a conversation about AI....?

Stuartv - Back then, we really did not plan dives like they are done now. We tended to plan around a purely NDL based profile. Most of us did not have any concept of a SAC beyond how much time at a depth a specific tank would get us. Nitrox did not exist. The training was generally more intense and a lot longer. While I used J valves, I have never not used a SPG (well maybe a couple of times). I tended to use either 1/3 or a specific PSI depending on what was going on. My ascent rate was also 60'/min and no safety stop (never had heard of them then). If you were doing restricted diving, e.g. cave/cavern etc, you tended to still use the current accepted considerations such as 1/3 in, 2/3 out. This is a part of having long term experience which new divers do not have. Some of us have a history and understanding of where things evolved from.

My comment was directed specifically at Charles :

Years of tradition, unhampered by progress, will always be a viable fallback strategy for many. I would still be comfortable using a J-valve and one double hose regulator, but I really do enjoy the advances that technology has provided and remain confident that the future holds even greater strides in the enjoyment of life underwater

It does not apply as the J valve was significantly improved upon by the SPG.

Oh and again for Charles, the single hose regulator that came out of the 60's (?) is still basically the same as is currently used. In fact most of the gear is the same with few differences. The biggest one is the materials being used. My 1974 Conshelf 2nd stage is almost form/fit and factor the same as many is use today. Even AI came out in the late 80's and early 90's.

 

[DevonDiver]

I'm accused of being a luddite, but not one serious response to my post about future uses and functionality for tech AI.

Technical diving innovations tend to trickle down to recreational diving. AI seems to be the only one being pushed upwards.... like a large suppository.

Reliability and cost issues aside... (but not forgotten)...

AI could be useful for the technical diver if it provided a warning that compared available gas against planned dive and deco schedule. It'd be a purely baseline safeguard... as the tech diver should have plenty sufficient gas. Nonetheless, the unanticipated can occur and divers have been left with insufficient deco gas before.

I'm not sure whether tech divers would want that comparison using ATR or pre-designated SAC/s. These could be: deco/resting (low), working (med), and elevated (hi). The computer could default to 'med' on the bottom and 'low' in deco...or the diver could pre-designate. The diver could also amend the SAC in-water as the situation dictated.

I think I'd prefer a pre-designated SACs... but an AI computer could simply warn if actual consumption deviated from that pre-designated SAC by a significant margin.

How I envision that'd work... The tech diver would have to program each transmitter into their computer, to include the gas type and volume of the tank. That'd be a timely process and would demand some personal and team protocol to prevent human errors in the pre-dive phase. The programming of the computer would need to be confirmed, as would the syncing of the correct transmitter to the correct input gas. The functionality of each transmitter would also need to be confirmed (maybe the computer could cycle through a battery check - as per modern CCR electronic checks)

As the dive progresses, the computer calculates the deco schedule as per normal, based on the gasses it knows the diver is carrying (this already happens with computers like the Petrel). At the same time, it predicts the necessary gas consumption/volume for each available gas needed to perform the real-time scheduled deco ascent. When the predicted gas consumption reaches 2/3rds of the known gas carried (rule of 1/3rds), it issues a warning.

Should any gas lose volume, or the SAC rise beyond pre-inputted predictions, then the computer would issue a warning. If a gas became entirely unavailable, then the diver would immediately de-select that gas from the computer. The computer would, as normal, recalculate the decompression schedule based on the new gas situation.

If the available (selected) gasses were predicted to be insufficient to allow the calculated decompression, then the computer could ask/suggest whether the diver wanted a bailout strategy - yes or no.

The diver would select 'no' if they could complete the designated deco using an 'off-sensor' gas supply (i.e. gas donation from team member).

If the diver had no 'off-sensor' gas supply, they'd select 'yes'. That strategy could then provide the 'best-chance' decompression based on what gas/ses were available. This could include:

1. Re-planning deco using other available gasses.
2. Changing the deco curve to allow shallower stops, if that extended gas supply sufficiently to allow acceptable deco.
3. Reducing conservatism to permit the best possible deco given limited gas.

Or a combination of all 3. Basically, it'd be an exercise in shifting Gradient Factors intelligently to allow the best off-gassing with what gas the diver had at their disposal.

However... the bulk of this could be done without AI on a current generation tech computer. It'd be relatively easy to provide a software solution to gas versus time; where the diver simply input the volumes of the gasses carried and their SAC rate/s. The computer can work out the rest, as it knows the depth and deco obligation. AI would still only provide a benefit if the actual SAC varied (unnoticed) from the predicted SAC or, potentially, where a partial loss of gas occurred.

Until now, tech divers have to do this mentally. The hardest tangible is predicting the best possible decompression based on an insufficient gas supply. There'd be considerable debate in the tech community on any algorithm that attempted to provide a solution to that. Honestly, I don't know if any computer manufacturer would want that liability....

I will leave it to the reader to decide whether they feel 'technical' AI would adhere to the K.I.S.S. principle.

 

[AJ]

Simple, no hose.

Ah, so loosing the hose would cost me € 200,- extra? Quite some innovation I must say.

 

[CuzzA]

Ah, so loosing the hose would cost me € 200,- extra? Quite some innovation I must say.

It would be the difference in price from the cost of your SPG and hose, maybe even a compass if the computer had one. Perhaps you would be savvy enough to buy when the transmitter is free or just wait until the price comes down, as I'm sure it will as WAI becomes more and more popular.

You asked what was innovative about the design and then once you get an answer you bring up the cost. You didn't say anything about cost in your original post, simply what was innovative. We've mentioned a dozen times throughout this thread what we would like to see from the future of WAI. Reduced cost is one issue. But for a new diver going straight to WAI with a compass built into the computer the cost would be a wash; however, they would have the benefit of hoseless data and some of the other utility we've already mentioned.