AI question - dive time remaining

[vladimir]

How's that work out if your buddy gets a freeflow at 130 feet?

That computer (Oceanic Atom 2) allows you to set a reserve of up to 1500 psi, as do many others. (Hopefully without inviting a lecture on Rockbottom.)

 

[ianr33]

That computer (Oceanic Atom 2) allows you to set a reserve of up to 1500 psi, as do many others. (Hopefully without inviting a lecture on Rockbottom.)

Thats good to know.

What would it do if the reserve is set to 1500 and you are at 20 feet with 1300 psi remaining? Does it get upset?

I'm not a fan of AI (as you can probably tell! ) Just not applicable to much of my diving,but each to their own.

 

[vladimir]

What would it do if the reserve is set to 1500 and you are at 20 feet with 1300 psi remaining? Does it get upset?

An alarm goes off. You're free to ignore it. I don't have an Atom 2, but my D9 allows me to disable all audible alarms, which I do, so I don't annoy myself or my fellow divers.

I'm not a fan of AI (as you can probably tell!)

I find [remaining dive time] worthless and I pay it no heed. I like having my gas data on my wrist; that makes AI worth it to me.

 

[FritzCat66]

What would it do if the reserve is set to 1500 and you are at 20 feet with 1300 psi remaining? Does it get upset?

This seems disingenuous. I mean, if you set your reserve at 1500 and you're already at 1300, then obviously you're not actually diving your computer then, are you? So, if we're going to talk about how good our instruments are when we totally ignore them, how is ignoring your AI computer any worse than ignoring your non-AI computer, or ignoring your SPG, or your bottom timer, or your watch, or your tables? How is ignoring it a criticism of AI at all?

Now, to address the situation anyway: I don't know how all AI computers handle situations like this, but I know that, with mine, if I got into trouble or ignored my warnings or something and got into this situation, the DTR display would simply show zero, with a flashing RES alarm indicating I am into my reserve gas, and otherwise still show its normal N2 and O2 meters, total dive time, current depth, and of course remaining pressure - all on one screen. Other relevant alarms - deco, PPO2, etc. - are still active and functional and may or may not be going off, depending on the specifics. I have obviously exceeded my parameters, so it's giving me all the information I need to make my own decisions about what to do, which is exactly what I would expect of it. How is that a criticism of an AI computer?

Or are you really trying to criticise how a diver uses their AI computer? If so, that's not a problem with the device itself, or even the whole category of AI computers, but rather one of diver training... just like most other dive issues.

 

[vladimir]

Or are you really trying to criticise how a diver uses their AI computer? If so, that's not a problem with the device itself, or even the whole category of AI computers, but rather one of diver training... just like most other dive issues.

I think that Ian's point is that the remaining dive time feature might get you to the surface safely under normal circumstances, but what if you need to share gas with your buddy? If it has been set to allocate enough air for you minus a reserve of, say, 500 psi, that reserve might not be enough if your buddy has a catastrophic gas loss at depth. If you set the reserve to what you and your buddy need for an ascent from the deepest portion of your dive, then it will be reserving far too much gas during the shallow portion as you ascend, defeating its usefulness.

 

[Bubbletrubble]

My personal experience tells me the exact opposite. I have seen more dives ended due to corroded o-ring spools, leaky HP hoses and stuck SPGs than I have seen ended due to synch issues with a wireless AI computer.

The tool is here and if you like the tool: learn to use it.

You listed several "failures" with an analog SPG. To be fair, the #1 cause of a leaky HP hose is a corroded o-ring spool +/- bad o-rings, which BTW should be one of those things that receives regular maintenance. I've found that corroded HP spools usually show signs of impending failure. Upon pressurization, pivoting the SPG should occur freely. If it doesn't, take it apart and re-lube...or replace the HP spool.

Air-integrated computers are still dependent on battery power. I'm surprised that you are asserting that an electronic gizmo is more reliable than an analog SPG. :shocked2:

It certainly used to be the case that strobes firing would interrupt the signal. It happened reliably with my US Divers Monitor 3. My more recent AI computers (Uwatec Air X, Air Z) rarely lost the signal. I have never caught my Suunto D9 in a signal lapse in about 300 dives. So I agree that the technology has improved quite a bit. I'm not so sure about your assertion that it's still not as reliable as an analog SPG, but that's what I'd expect.

@vladimir: What happens if your tank valve is shut off and reg de-pressurized? Do you have to re-pair the wireless receiver and transmitter? Just curious.

 

[vladimir]

@vladimir: What happens if your tank valve is shut off and reg de-pressurized? Do you have to re-pair the wireless receiver and transmitter? Just curious.

Yes, but the pairing process consists of pressurizing the regulator with the wrist unit nearby. If it's on your wrist, it's hard not to pair it.

 

[FritzCat66]

If you set the reserve to what you and your buddy need for an ascent from the deepest portion of your dive, then it will be reserving far too much gas during the shallow portion as you ascend, defeating its usefulness.

You're not seriously criticizing a DTR calculation and display because of its inability to anticipate emergency situations, are you? Because no method can do that, old tech nor new tech, analog nor digital, rule-of-thirds nor AI preset reserve pressure... unless and until someone invents a scuba crystal ball.

Or, again, are you criticizing a diver who is untrained and mindless enough to think that a DTR is the absolute and only indication they need, and can ignore all the other information being displayed on their AI computer? In which case, how is that a criticism of AI and DTR technology and not one of a diver who hasn't been properly trained and doesn't understand how to use their instruments?

Sorry guys, your complaints about AI itself are all just sounding like old hayseeds grumbling about "them newfangled gizmos" without any hard rationality to back them up. Conversely, complaints about training, interpretation, things regarding the diver's utilization of AI - and maybe even concerns about complacency - might be valid, but those should not be directed towards the technology itself.

 

[ijdod]

So far the only thing that bothered me was that I couldn't disable the RGT number on the AI computers that I used. That number is pretty meaningless in my opinion. I'd rather see a bigger raw pressure indicator, or perhaps actual SAC rate.

 

[vladimir]

You're not seriously criticizing a DTR calculation and display because of its inability to anticipate emergency situations, are you?

No, actually, I was explaining what I thought Ian's criticism was. I'm sure he'll correct me if I was wrong. Personally, I just ignore the DTR display.

Because no method can do that, old tech nor new tech, analog nor digital, rule-of-thirds nor AI preset reserve pressure... unless and until someone invents a scuba crystal ball.

Actually I think keeping an appropriate gas reserve for you and your buddy is easily accomplished with a little mental arithmetic or some simple rules of thumb. You might need a crystal ball to accurately predict an emergency, but to anticipate one, all you need is a little training and experience.

Or, again, are you criticizing a diver who is untrained and mindless enough to think that a DTR is the absolute and only indication they need, and can ignore all the other information being displayed on their AI computer? In which case, how is that a criticism of AI and DTR technology and not one of a diver who hasn't been properly trained and doesn't understand how to use their instruments?

How is the DTR data useful if you have to constantly back out a gas reserve? It doesn't simplify anything. It's easier to just look at your gas supply.

Sorry guys, your complaints about AI itself are all just sounding like old hayseeds grumbling about "them newfangled gizmos" without any hard rationality to back them up.

I've been using AI since it was introduced, in the early 1990s, and continue to do so. There is nothing "newfangled" about it to me. I am glad you have finally discovered it. After a while you might have a more objective view of its limitations.