Why the dislike of air integrated computers?

[rhwestfall]

I agree with Stuart here.

I personally don't do it, since I love my Petrel and I don't want a transmitter on one of my first stages. However, the one reason that I would consider WAI would be because I'm a data junkie, and it's nice to have an accurate SAC rate. As the tech divers here know, that number is crucial for gas planning.

Yes, you can do the math by recording pressures, average depths and times, but you can get much more accurate data with a WAI computer, especially if you want to track changing SAC rates with different types of dive, with and without a large DSLR, etc..

With most tech training, you calculate this once or twice during training and use that as your SAC rate. Might be good to have a current, accurate number for each dive without having to do that note taking exercise every time.

it is additional task loading during a dive, but I occasionally will log on my slate the dive time and the pressure at or surrounding some event. I can then extract the depth info from my Pertal, have an average depth (spreadsheet/math), and with some more math, I have an idea of how my air consumption was in that portion....

 

[RJP]

It worked fine... until I tried to check my valves while on the boat. I almost twisted one of the transducers off as it felt like a valve knob. I reconfigured to have both of them pointing in and found that they interfered with grabbing the isolator knob. So, unless I went with a short hose that got them out of the way of the manifold, I would not use AI to dive back mount doubles. Perfect for side mount, less than optimal for back mount, at least with these regs.

I guess I might use a first stage swivel and a short hose to tuck it out of the way - if I was going to utilize AI...

This is not a universal problem when diving an AI transmitter. With AL Legends the transmitter is completely out of harm's way.

If something is going to bump/grab/knock my transmitter that means it has already sheared my tank valve - or my head - completely off. In either case, a damaged transmitter is the least of my worries.
:shocked2:

But seriously, I've done probably ~600-700 penetration dives with the transmitter configured as seen above. Another 300-400 non-penetration and/or single-tank dives. Figure 70 or so of those were mounted on an AL80 and thrown in and out of a pickup truck and driven all over Bonaire. Between various dive trips assume 250 or so dives with various charter boats and dive ops all over the world. Never had a crew member or fill-station attendant try to grab the transmitter thinking it was the valve handle. Also note that I am not gentle with my gear in any way. Over the course of ten years there's barely a scratch on the transmitter.

Could it be a potential problem? Sure. And maybe in the next ten years and the next 1,000 dives I might experience one.

 

[rhwestfall]

This is not a universal problem when diving an AI transmitter. With AL Legends the transmitter is completely out of harm's way.

If something is going to bump/grab/knock my transmitter that means it has already sheared my tank valve - or my head - completely off. In either case, a damaged transmitter is the least of my worries.
:shocked2:

But seriously, I've done probably ~600-700 penetration dives with the transmitter configured as seen above. Another 300-400 non-penetration and/or single-tank dives. Figure 70 or so of those were mounted on an AL80 and thrown in and out of a pickup truck and driven all over Bonaire. I am not gentle with my gear in any way. There's barely a scratch on the transmitter.

Could it be a potential problem? Sure. And maybe in the next ten years and the next 1,000 dives I'll experience one.

What, no turret? No "fifth port"? Surely diving this rig, you are going to .....

 

[Adobo]

As I look forward, it SEEMS like I MAY choose to add my AI transmitter into my configuration later. The reasons I think (now) for that would be that it would give me additional monitoring and data collection on my usage of my back gas. The fact that I would not have the same info for my deco gas does not take away from the value of that info for my back gas. Plus, I anticipate that back gas consumption will occur while I'm focusing on other things. Reviewing the data to see what my consumption was during the different parts of a dive seems just as useful after a tech dive as it is to me, now, after a rec dive. OTOH, when I'm using my deco gas, I expect, generally, to be doing nothing but "hanging". So, while finely detailed consumption data might be nice, I don't think I would get as nearly as much benefit from it as I would from back gas consumption data. For deco gas, I will know start time, pressure and depth, and end time, pressure and depth, and I think that will probably be adequate deco gas data to facilitate good future gas management planning.

Each diver will associate a certain value of knowing their SAC rate on backgas. If it has value to you, then it is worthwhile. For me, I've done the math enough times that I know what it is. If I am diving a lot, it goes down a smidge, if I am dry for a while, it goes up. For planning a dive, I know what numbers to use.

Having the data real time wouldn't personally help me. I mean, if the number is higher than predicted, there isn't anything I can do about it anyway. Some people might use that data to deduce that they are getting their butts kicked during a dive. I kind of know if I am getting my butt kicked without looking at the SPG and am already actively looking for ways to make the dive more relaxed. A higher than predicted SAC rate could affect your planned bottom time but again, what do you do about it during the dive beyond what you would do if you realized that you are working hard without the SAC rate numbers? The dive ends when you want it to end - usually when you have reached the planned exposure (depth/time combination) or are at min gas. I mean, you can shallow the dive a little to extend bottom time but the savings in gas executing the dive at 140 instead of 150 is going to be negligible anyway.

For me, the data I could really use real time and after the fact is my SAC rate during deco. SAC rate should be .5 cf/min or less ideally. If my SAC rate is higher than that, it means I am working during deco. Maybe my buoyancy isn't dialed in or I am subconsciously finning.

So again, some divers, that backgas SAC rate for every dive might be useful. Those without AI could do it but it would be tedious. I kind of kept track of it the first few tech dives but haven't really paid much attention since. Others might be more interested so having a zero intervention system that tracks it for you might be a benefit. For me, if anything, I'd like it on my deco gas.

But to put this into context of the original question... AI has a lot of benefits - real time SAC rate, air time remaining, bottom time remaining, and perhaps other things I am not aware of. I could imagine that some tech divers don't invest in AI as the benefits are not applicable to the various elements of their tech diving. So then the question for those tech divers would be, is it worth it to invest in it if the benefits are largely around their recreational diving?

I imagine the answer for some would be, yes. For some, no.

---------- Post added August 5th, 2015 at 10:19 AM ----------

I just spent a week on the MV Spree tech diving the artificial reefs here in the Keys on back mount doubles. I used only my AI for checking air: no mechanical SPG attached. It's been years since I dove back mounted doubles, so I had to quickly throw a set together. I used the first stages from my side mount and the short/long hose configuration from my single tank reg. I went ahead and left both transmitters on the first stages. It worked fine... until I tried to check my valves while on the boat. I almost twisted one of the transducers off as it felt like a valve knob. I reconfigured to have both of them pointing in and found that they interfered with grabbing the isolator knob. So, unless I went with a short hose that got them out of the way of the manifold, I would not use AI to dive back mount doubles. Perfect for side mount, less than optimal for back mount, at least with these regs.

Does the computer give you a relatively easy interface so you can toggle across each tank to see their pressure? What do you do when you dive stages in addition to your sidemount doubles? What do you do with deco bottles? Or do you not bother with AI with anything other than your *main* bottles?

 

[RJP]

What do you do when you dive stages in addition to your sidemount doubles? What do you do with deco bottles? Or do you not bother with AI with anything other than your *main* bottles?

For me anyway. But I'm crazy enough to only have one transmitter on my backgas. So, there's that...

 

[stuartv]

But to put this into context of the original question... AI has a lot of benefits - real time SAC rate, air time remaining, bottom time remaining, and perhaps other things I am not aware of. I could imagine that some tech divers don't invest in AI as the benefits are not applicable to the various elements of their tech diving. So then the question for those tech divers would be, is it worth it to invest in it if the benefits are largely around their recreational diving?

I imagine the answer for some would be, yes. For some, no.

My Atom does not give me real-time SAC. It just shows current tank pressure and ATR in real-time. I look at RMV data after downloading to my PC.

As far as being "worth" it as I advance in Tech diving, my thought is that. I like AI and would like to continue to have it for Rec diving, for sure, and might like to have it for Tech diving. At least/especially at the beginning of my Tech "career" while I'm still learning my RMV under different conditions and, hopefully, while it's still improving.

So, my current choices (that I'm choosing to consider) are, either, keep my Atom and use it with AI on a Rec reg set, use it in Gauge mode for Tech stuff, and buy a Petrel 2 for Tech use. Or, I could not buy a Petrel, sell the Atom, and buy a SeaBear H3 with wireless AI to use for Rec and Tech diving.

In either scenario, I would keep the Aeris A300 computer I have, to use as a backup - in gauge mode where appropriate.

Part of my personal valuation is that I personally would prefer not to have a computer as large as the Petrel on my arm when I'm doing recreational dives. Or, really, ever, actually. But, if I'm doing a tech dive, with doubles, slinging a deco bottle, etc, it definitely seems like it would be less of an annoyance versus diving in a thin wetsuit or less, with a single AL80 and wanting feel somewhat minimalistic.

As a "worth" evaluation, I think the H3 option would meet my needs for less cash out of pocket. And give me a form factor that I prefer in all scenarios, plus give me wireless AI in my primary DC in all scenarios as well. Win, win, win. I think. Pending details and pricing on the H3 AI, of course, and a bit more real world usage reporting on the H3 itself.

IOW, the statistics of the answer to the question of whether hoseless AI is "worth it" to tech divers may change quite a bit once there is a tech computer available that people regard as reasonably comparable to a Petrel and that also offers AI.

 

[Diving Dubai]

Although my computer gives realtime SAC it's a mere curiosity given that no two dives are the same. It can be useful overtime to see if you average SAC is reducing (or increasing) for whatever reason. Likewise the Air time remaining - or as I like to refer to it, Time To Die meter is not something I use, experience tells me that at any given pressure/dive time how long my dive time will be.

Apart from the obvious data points (Depth, tank pressure, NDL & dive time) the only other real data I use live is my PO2 when deep.

I do have transmitters on my stages and deco too because I can

 

[EFX]

I searched the thread for "batter" and found some interesting replies but none that answered the following two questions:

The battery power in your transmitter gets low.
(1) Will it continue to transmit pressure? If so,
(2) how much time do you have before it stops transmitting?

The implications for diving in OH environments are clear.

 

[RJP]

I searched the thread for "batter" and found some interesting replies but none that answered the following two questions:

The battery power in your transmitter gets low.
(1) Will it continue to transmit pressure? If so,
(2) how much time do you have before it stops transmitting?

The implications for diving in OH environments are clear.

I did 28 dives over the course of a week-long liveaboard trip with the low-battery indicator telling me to change the battery in the transmitter.

 

[dmoore19]

Changing the battery on a transmitter(oceanic) is cheap and easy. I have a spare battery in the bag and usually change it anyway before a trip.