tank pressure redundancy

[GrandpaScuba]

Most users of AI computers don't bother with redundant gauges, or at the most just keep an SPG in the save-a-dive kit.

I used to do the above, I had an AI computer w/hose and sometimes, a non-AI wrist mount computer for "backup". This was until about 6 weeks ago. I was diving with another instructor and a class when, as I got to about 30ft the screen of my AI computer went completely blank. It was early in the dive, so I knew I had lots of air, but didn't want to just keep going with a class until I ran out of air. So, I sent the class off with the other instructor and I made my way back to the beach, underwater.

After that, I replaced my hosed (pun intended) computer with a plain SPG and added a hoseless AI computer (Uwatec Smart Z). So now I have reduntant tank-presure monitoring and if I want redundant depth/time, too, I just add my non-AI wrist comptuter. (btw, if I do use both computers, that doesn't mean I have 2 on my wrist. I keep the Uwatec computer on a retractor-slate.)

 

[ArcticDiver]

Actually, as has been pointed out, once a person has a pretty good idea of their gas consumption tank pressure indicators are more of a reality check than a vital instrument; for a known dive profile.

In life critical operations there is always either a multiple computer or a human backup. In the case of a diver one can either use multiple SPGs; hoseless AI and mechanical preferred; or, just make loss of gas measurement a dive abort event.

Actually, the more a dive approaches the edge of the envelope the more one should use one or more dive computers. A machine to monitor parameters, accurately measure events and make vital calculations is a significant contribution to dive safety.

 

[donnad]

we went ahead and ordered hubby the tiny tusa spg and he's gonna put it on a retractor or slip it in his cummerbund. it's very slim, so won't be in the way. i'd sure prefer him to have it..........i don't wanna be aborting our dive if his fancy schmancy computer goofs up on us! and we carry dive watches for backup timer.

 

[spectrum]

we went ahead and ordered hubby the tiny tusa spg and he's gonna put it on a retractor or slip it in his cummerbund. it's very slim, so won't be in the way. i'd sure prefer him to have it..........i don't wanna be aborting our dive if his fancy schmancy computer goofs up on us! and we carry dive watches for backup timer.

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

 

[Doc Intrepid]

You made a point of saying "NOT hoseless". An AI computer directly attached to the tank. No transmitter.

The probability of a device failing that is directly attached to the tank, e.g. not relying on an electric signal from a transmitter, failing to accurately track tank pressure approaches zero assuming the battery is good. Replace the battery periodically and don't worry about it. There is no particular need to carry any redundant SPG.

 

[beach89]

I really don't understand the fear that some divers have for electronic equipment. When properly designed and maintained, electronic devices are just as or more reliable than mechanical ones. And if my AI computer fails, then I'd do the same thing that I'd do if my regulator failed; I'd abort the dive. Personally, I'd bet that regulators, which are mechanical, fail a lot more often than dive computers. And a lot more divers have died because of those failures.

 

[Soggy]

What problem are you trying to solve that makes you want the AI computer?

 

[Charlie99]

Personally, I'd bet that regulators, which are mechanical, fail a lot more often than dive computers.

I'll take that bet. When out on dive charter boats I've seen many wireless air integrated computers. The vast majority are probably nothing more than a dead battery in the transmitter unit screwed onto the first stage, and are therefore relatively avoidable, but it still seems to happen much more frequently than regulator problems.

Fortunately, most computer problems are noted when they don't fire up before the dive; and even if the problem occurs underwater, a prudent diver will always know that he has enough gas for both him and his buddy to safely abort the dive, so a computer failure should be nothing more than a minor nuisance.

 

[donnad]

my bad. he ended up going with the hoseless..........so we decided on the spg for backup tank pressure/depth. he dove with a rented hoseless ai one time and really liked that "biofeedback" so to speak. me...........i don't feel like i need that.......the simpler the better....so i got the aeris xr2 wrist mount.

 

[redacted]

What problem are you trying to solve that makes you want the AI computer?

Overweight wallet?