tank pressure redundancy

[nvert]

FWIW, this is my experience....

I chose to dive AI wireless with a D9 and use a small Dive Rite SPG as a backup - and maybe really - as reassurance that the D9 was actually working as it should. However, the Dive Rite SPG kept reading that I had around 400psi of air than my D9. I shrugged this off for a looooooong while thinking that the D9 was simply being conservative - just as the Suuntos are recognized for. But, while on a dive boat last month, I checked my tank with an analogue pressure gauge owned by a very meticulous diver who double checks all his tanks before hooking up his regs. The pressure reading from this device perfectly matched the pressure reading of the D9. The Dive Rite had been off 400psi all this time!

So now, 118 dives later with a wireless computer, I have faith to drop a hose. These computers are tested, retested and then re-retested long before the diving public can buy them. For the recreational diver with good diving skills, diving awareness and who actually learns to use(know) the darned thing, I see no strong argument against going wireless. Heck, its true computers really do PERMEATE our lives oftentimes in ways so small but with the greatest impact *without our choice*.

I will replace the spg but it's going to stay on the boat. And, just like any dive equipment that malfunctions - mechanical or electronic - one should terminate the dive. Computer or not, to me diver responsibility/preparedness NOW becomes the fundamental issue at hand. Kind of ironic too since this was also the fundamental issue at the beginning of rec sport diving.

 

[ArcticDiver]

Why Hoseless Air Intregration?

I want a reliable method of matching the reality of my dive against my dive plan. My computer measures actual depth, actual gas consumption, etc and gives me a real time picture of my gas and decompression status.

-Originally I went hoseless because I didn't want the extra "stuff" hanging around to clutter things up. Now, that multiple transmitters are available I'm staying that way to be able to monitor all my tanks.

In my personal case I also carry a SPG. But that is because when I'm on a trip with a lot of expensive dives at stake I don't want the one in a million kind of malfunction to mess up the trip. So far except for the occasional independent double situation I've never used the spg except to see if it is there and working.

 

[Soggy]

I want a reliable method of matching the reality of my dive against my dive plan. My computer measures actual depth, actual gas consumption, etc and gives me a real time picture of my gas and decompression status.

How does the wireless air integration provide you with this information any better than a SPG?

 

[ArcticDiver]

How does the wireless air integration provide you with this information any better than a SPG?

Read, think and understand.

What does the computer do?

What does it calculate?

How often does it do that?

What data does it integrate?


How could a person in a practical way do that?

Hint: A person can estimate and make some pretty good guesses. But, they are guesses.

 

[Soggy]

Read, think and understand.

I have done this long ago, which is why I use a bottom timer and simple pressure gauge.

Hint: A person can estimate and make some pretty good guesses. But, they are guesses.

The computer is only making estimations, too, based on models and abstractions that only remotely resemble human physiology. But, I'm not trying to argue computers here...I'm asking you what useful information the air integration provides you during the dive.

 

[ArcticDiver]

I have done this long ago, which is why I use a bottom timer and simple pressure gauge.



The computer is only making estimations, too, based on models and abstractions that only remotely resemble human physiology. But, I'm not trying to argue computers here...I'm asking you what useful information the air integration provides you during the dive.

No the computer is not making estimations on gas, actual depth, rate of consumptiom, etc.

Yes, the tables you use whether from paper (to you) or in some type of surface or underwater computer are models based on the best guess of how the human body responds to underwater envioronment.

I went back and looked at some of your prior posts. You appear to have a luddite philosophy that fails to consider that the information you use to plan and execute a dive are computer produced. You are certainly welcome to have luddite behaviour. That is your privilege. But that does not negate for the rest of us the obvious and real benefits to using a dive computer.

 

[Soggy]

No the computer is not making estimations on gas, actual depth, rate of consumptiom, etc.

My SPG doesn't make estimations either and calculating your consumption rate is pretty trivial.

How is that "additional" (it's not additional, it's the same information, but you think it's additional) information help you out during a dive?

You still haven't told me one single useful thing that the air integration provides you.

I went back and looked at some of your prior posts. You appear to have a luddite philosophy that fails to consider that the information you use to plan and execute a dive are computer produced.

Yeah, I'm a luddite computer programmer. LOL.

But that does not negate for the rest of us the obvious and real benefits to using a dive computer.

Which are? You still haven't answered my original question.

 

[nvert]

This is going in circles. but here's my answer on AI "usefullness"....

One useful bit of info my AI provides me with (that the spg+timer can not *directly* do) is show me the *time* I have left on my tank based on my current breathing rate + depth + psi. Oviously, this information(estimation) changes throughout the dive as my depth and/or breathing rate both affect psi. The spg + timer + depth gauge (computer or analogue) provides the diver with the same information but, realistically, how easy is it to constantly determine the component of time when time is affected by these ever changing variables? One could argue that psi, depth, and bottom time is probably all you need to make a safe dive - agreed - I just like the additional piece of calculation.

My AI has also been a teaching tool. Since my AI provides me with info regarding my remaining psi and a timer "countdown", it has helped me better understand how all these variables affect my diving. I watch the relationship between my breathing, depth, tank pressure and time *during* my dive and that has informed me to better my diving awareness and understanding - change my diving behaviors, better control, etc. Again, something that generally comes to any diver who constantly strives to better their diving abilities.

In any event, whether AI or not, dive safe, dive knowing.

 

[redacted]

One useful bit of info my AI provides me with (that the spg+timer can not *directly* do) is show me the *time* I have left on my tank based on my current breathing rate + depth + psi. .

I dove with a pick-up buddy who used an AI Oceanic computer while I was diving with a Data plus. He kept comparing our displays and acted alarmed that I had more time remaining than he had. But he was looking at "air time remaining" which also subtracted his reserve gas while my computer merely advised me what my N2 loading status was in terms of NDL. It was my impression that it detracted from his diving enjoyment.

 

[Arcaporale]

Good move.


As far as I am concerned the less I rely on underwater electronics the better. If he must have the AI toy then backing it up is prudent.

Many good arguments have been made regarding knowing your air pressure before the thing crashed and then ending the dive safely or having your buddy's air handy but they are only partial solutions. There can be situations where you need to know what you have in that cylinder (period) and knowing so can let you end the dive safer in a host of ways. Examples would be making it back to a preferred exit or surfacing location of doing a slow ascent with full stops. Adding the analog SPG closes the gap.

This whole streamlining thing is waaaay overrated IMO.

Pete

Adding another gauge for redundancy is just silly, esp. if you doing just recreational diving. The failure of a guage isn't gonna cause you to die, as soon as one of your instruments fails you should be on your way to the surface, regardless if you have a backup. You don't need to know how much air is left when your AI computer fails because either you have enough air to complete a safe accent or you don't, if you don't have enough air, then you soon find out durring your accent and then are only left with the option of ditching you weight and going to the surface, this is only assuming your buddy isn't around to give you air. If you are so concerned with failure you shouldn't add another SPG, because that only adds to the amount of potential failure points on your rig. Even technical divers with doubles and two regulators use only one gauge.