Why the dislike of air integrated computers?

[ev780]

I was thinking the same thing, modern minimalism, embracing technology in an effort to reduce clutter even if it's just an SPG. It's one less thing dangling even though clipped off. I guess if I used my unbalanced MK2 with an unbalanced poppet second stage and loosely kept track of time if the computer quit, I could end my dive when the thing slowly started to breathe hard. One thing I refuse to do is end a dive 5 minutes into it if my AI hoseless computer craps out. Perhaps that's where years of guessing air supply with a watch and depth gauge might come in handy.

Well stated!!!

And really I don't worry too much about failure of the AI stuff. My experience has been that it fails at the same rate as any other piece of gear. It is a mechanical thing and it will break just like the rest of our kit. When it does adapt and get it fixed. If redundancy is needed then redund! If the dive conditions make failure not that big of a deal then don't redund. For me a gear failure just causes me to end a dive early, fix the thing and get on with it. AI is priceless to me.

 

[dmaziuk]

When Air Time remaining becomes low or zero, if you need to share air with someone, you may not have enough to get both up to surface. Of course, it will depends on your reserve setting the depth that you need to start sharing air. Just something to keep in mind when relying on ATR

While this is obviously true, how is it different from having 700 psi on the spg and suddenly having to share air? What this argument really is, is atr bad because it shows minutes, spg good because it shows psis.

 

[kimbalabala]

My husband and I both got the Oceanic HUD Mask. His wouldn't sync consistently. We joked that there must be some metal in his head. He returned it and got another Oceanic AI computer and likes it. I love my mask. I like the fact that I don't have to look down to see anything- my ATR, depth, air - it's all right there with the push of a button - and when an alarm goes off I actually hear it! I hate it when I hear alarms and don't know whose it is. With the computer on my head there's no doubt I'll hear it. I also dive with a Cobra just in case something goes wrong. AND we have both experienced our Cobra's dying and they had to be sent back for a fix. My husband always brings along a regular SPG for redundancy - but only if our AI's die.

 

[eelnoraa]

While this is obviously true, how is it different from having 700 psi on the spg and suddenly having to share air? What this argument really is, is atr bad because it shows minutes, spg good because it shows psis.

I never start my ascent at a fixed spg reading. What you should do is to ascent when you hit "rock bottom" gas supply. The rock bottom value is what is needed to take 2 divers to the surface following safe ascent procedure, completing all necessary stops, and with divers at stress breathing rate. The amount of gas is depth dependent. I hope this part make sense and can be agreed upon.

The actual PSI value depends on tank as well. With AL80, at 100ft, I will start my ascent at ~1500psi. At 80ft, it is ~1200psi, at 60ft ~900psi.. It is actually quite sad that OW class don't teach proper gas management anymore.

 

[boulderjohn]

It is actually quite sad that OW class don't teach proper gas management anymore.

When in the past did OW classes teach proper gas management?

The old PADI class had very little. The current one has quite a bit more. So at least as far as PADI is concerned, modern OW classes teach much more gas management than they did in the past, not less.

 

[phoenix31tt]

I personally don't agree with having enough reserve gas for a safety stop though... Just enough to get the divers to the surface... It's wasting dive time imo for something that really is just precautionary [emoji4]


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[eelnoraa]

Maybe not be in PADI ciricullum, but I know quite a few instructors in PADI organization teach this in OW. The real problem is not all instructors actually know and understand this concept. In AOW deep dives, my instructor told me "signal me when you heat about 900psi, and we can ascent". We were diving to 100ft. He has HP100, but I only have LP72. We didn't need to share air, but imagine if we need to.

---------- Post added July 22nd, 2015 at 04:58 PM ----------

I personally don't agree with having enough reserve gas for a safety stop though... Just enough to get the divers to the surface... It's wasting dive time imo for something that really is just precautionary [emoji4]


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If you do the math, the real killer here is NOT the time you spend on safety stop. It is the elevated breathing rate when someone is in stress at the deeper portion of the ascent. The stop(s) don't happen until reltively shallow.

Take stress SAC=1, 30ft/min ascent rate, 2 divers ascent from 100ft to 50ft will consume 17cf, that is almost 700psi in AL80.

 

[Adobo]

It is actually quite sad that OW class don't teach proper gas management anymore.

In my OW class, they gave me the old "be back at the boat/beach with 500psi" routine. I knew enough to ask, "when do I leave the bottom so I make it back with 500psi?" Sadly, all I got was, "it depends."

It is really pretty sad given that the math involved is grade school level.

 

[dmaziuk]

It is actually quite sad that OW class don't teach proper gas management anymore.

My PADI OW included swimming up on a single breath doing the "huuuummmm...". The point being that OOA is an emergency. An uneventful vacation reef dive to 70' is "not emergency". This is risk management, not air management.


Do you drive an abrams tank in case you get hit by a jackknifing semi one day or do you drive a prius in case you have to pay for the gas every day?


For air management I was told to go dive more. Getting back to topic, that's where I think AI is very valuable: you can actually see your air consumption on the plot in your dive log software, right next to the depth, time, and water temperature. Of course that only works for geeks who look at the charts.

 

[Adobo]

My PADI OW included swimming up on a single breath doing the "huuuummmm...". The point being that OOA is an emergency. An uneventful vacation reef dive to 70' is "not emergency". This is risk management, not air management.


Do you drive an abrams tank in case you get hit by a jackknifing semi one day or do you drive a prius in case you have to pay for the gas every day?


For air management I was told to go dive more.

So your plan is, if you buddy has a gas emergency, your buddy will CESA from 70ft instead of asking you, who might be just 10 ft away, for gas. Is that right?

That's an interesting way of doing gas planning.

Getting back to topic, that's where I think AI is very valuable: you can actually see your air consumption on the plot in your dive log software, right next to the depth, time, and water temperature. Of course that only works for geeks who look at the charts.

Actually, the *original* topic of this thread is, why do people dislike air integrated computers.