convenient yes, but is it safe?

[g1138]

I've heard some AI's being inaccurate when you get to a very low tank. I've heard that some AI's tell you your SAC rate on the fly. I've heard AI's make you feel cool when you can say "I have 2467psi left".
I haven't heard of AI's being consistently unreliable or unsafe though.
I think they're safe, but I would always carry an analog SPG. Air's one thing I can't go without knowing.

All of my friends (minus 1) who use wrist AI's also have an analog SPG, usually a brass-chrome 2in dial on a short hose.
Also all my friends who have used wrist AI have had to scream at one time or another "THAT IS NOT A HANDLE!"
YMMV


Edit:
Regarding your original post. Next time you lose your computer, be sure you have a depth gauge with your SPG and watch before you continue your dive.

 

[TSandM]

My husband uses a Vytec with a transmitter. It occasionally refuses to sync at the beginning of a dive, and it will NOT resync after pressure goes to zero (a problem for technical divers doing valve drills, but not so much for recreational divers). The batteries have a fairly short lifespan, and give no warning that they are going to fail. For these reasons, I do not think it's a great idea to jettison the non-transmitted method of measuring pressure, whether that is an analog SPG or something else. (My husband still uses a Cobra that we bought when we started.)

But computers with transmitters are expensive, and it is a good question as to whether the additional value you get from buying one is worth the cost. There really is no need to monitor your pressure on a minute-to-minute basis, the way you should with depth and time. Checking gas every five minutes is generally quite adequate, and as you gain experience, you may even stretch that a little bit, depending on the match between the depth of the dive and the gas supply you took with you.

I'd take the money you were going to spend on a transmitter-capable computer and take more dive training.

But go diving with Claudette first

 

[Peter Guy]

As the spousal unit with the Vytec/transmitter, here is my take -- I really like having the information on my wrist but, honestly, if we hadn't had the Vytec I wouldn't buy one just because it is an AI unit. It is a "nice" but not a "must have" -- OTOH, if the $ is not a factor, why not?

That written, I always dive with a backup (which is really my primary) which happens to be a Cobra. Why a Cobra? Because we bought them when we first started diving since that was what seemed to be the right gear at the time. When the Cobra dies (and the spare one just did), I won't get another, but will go with a Brass/Glass SPG. Likewise with the Vytec -- when it dies, Oh Well -- it was nice.

I have had sync issues with the Vytec under the following situations:

a. Turning on the gas/pressurizing the transmitter, and then having to depressurize it -- for example, when an O-ring hasn't seated properly or when I've done a valve drill (doubles) which includes shutting down the valve and depressurizing the reg (and now I don't do that just out of cuzzedness). I've tried to find a fix for this, and maybe there is one, but I haven't figured it out -- but you should be able to depressurize/repressurize and still get a sync, shouldn't you? (And if anyone has a fix, please let me know!)

b. On a scooter -- My Sierra will sometimes interfere with the sync but it has always reacquired so it just is an annoyance.

BTW, at the start of the dive, I usually check both my Cobra and my Vytec to make sure both are reading and working.

Also, the Vytec DOES give warning of when the battery is running down but the Transmitter doesn't. As a result, I just have the batteries replaced once a year (doing around 150 dives/year).

Lastly, as far as I know, there is no indication that the pressure sensors are any more, or less, accurate than analog sensors.

 

[Rascally Rabbit]

If you're only diving shallow or with a large gas supply then "MAYBE" you can safely get away with being laxed about monitoring your gas pressure. As for a fix for the Vytec there is none. It is poorly engineered for dives you have intended this is due to the fact that the computer scans for a transmitter when turned on and the transmitter only transmits when under pressure. Once the computer is wet it doesn't scan it locks to the code it originally scanned while the transmitter rotates it's code at every turn on. For this reason I dive Oceanic computers. Each transmitter has it's own unique code that does not change. THe code/s are preprogrammed into the computer before diving by the user and remain in the computers memory until changed or battery replacement.

Again, let me suggest that many AI users are not fully aware of how their equipment functions. I'd suggest if you are interested in using technology you really learn to understand the particular model before even purchasing let alone before using it to dive. The Vytec is capable for a single tank user without shutting the tank valve underwater if you are careful to turn on and sync the computer away from another Vytec user. If you are to close to another transmitter when attempting to sync you run the risk of syncing with the wrong transmitter. (something else the user should be aware of)