SPG with AI computer?

[Bigbella]

Much more experienced divers than you are carry a spare mask if there is a chance they would lose their mask. You won't be able to do what you think you can do easily or safely.

I frequently use a full face mask for work -- and it was protocol from day-one to carry a conventional "split" mask and safe second, pony, etc., in the event of an emergency . . .

 

[PaulVS]

So we're all agreed then.

 

[BoltSnap]

So we're all agreed then.

Yep, typical SB discussion, always in agreement

 

[Boarderguy]

Yep, typical SB discussion, always in agreement

@PaulVS just don't use a SP and you'll be fine.

 

[Belzelbub]

Tip. The battery is one key failure point on AI transmitters, but it is very manageable. I have all of my AI transmitters on a regimented battery replacement schedule. I replace them proactively well before their theoretical battery life. YMMV.

Yep. Same here. Batteries are cheap. I do preventive maintenance on my gear usually in January or February. The batteries in the transmitters get replaced at this point. This is generally well before they would be due for replacement, but it works for me, and the cost is well short of what it costs to actually dive.

 

[KenE]

What computer and transmitter? I've never heard of that. Sounds more like something blocked your transmitter input and was cleared when you changed the battery... def an oddity

Suunto, normally it would blink when getting low. This time no blink, no warning, just steady 2356 psi. I do replace the batteries on a regular schedule and this occured two months before scheduled replacement. I checked battery and it was definitely dead, not just low as in the past. I found it odd that it would not give a warning. Those of you thinking I dove more this year, hold that thought, not true, schedule is on number of dives and time, not one or the other.

So, long story short, a Perdix 2 AI is in the budget this year. I will re-assess SPG after diving both for awhile.

 

[Bigbella]

So, long story short, a Perdix 2 AI is in the budget this year. I will re-assess SPG after diving both for awhile.

Cheap-o insurance:

 

[Seaweed Doc]

Interesting to me that the discussion turned to mechanical failures. I'm guessing you all are better divers than I am. My failures with these devices is exactly that, MY failures. Given my general incompetence, I'd suggest the SPG as backup is a good idea, at least at first.

My errors:

1. Forgot that my computer warned me that the TX battery was getting low. Yup, the next dive it was not just low, but nonfunctional halfway through. (And be careful if your computer tells you battery level: Some systems suggest the battery is full or nearly so, then appear to drain rapidly. Once it starts to go, replace the battery.) This was after using the computer for oh, 4 years or so.

With other equipment I've used (data sondes deployed underwater), my team learned that about 1 in 8 C batteries were defective out of the box. We learned the hard way, and henceforth tested each battery before use. Hasn't occurred to me, but might be a good idea to make sure that battery you're about to install has the rated voltage out of the box....

2. At first I didn't realize that I had to acknowledge a comms failure in order to see pressure again. Turned out the communication issue resolved pretty much instantaneously, but I didn't realize I had to press a button to clear the message and actually see remaining pressure. Now I realize the protocol, it's still mildly annoying when the TX temporarily fails. I don't realize it until I want information and then can't get it quickly. While teaching, I don't want to be futzing with my own gear, clearing an error.

Somebody earlier suggested dual transmitters and computers. I don't have a problem with that, though others note some electronics interfere with signal. Presumably such electronics could interfere with two transmitters. Never had issues with this myself, and I suppose if money were no object I'd buy a second Tx/computer setup.

FWIW, I route the SPG under my left arm and pin it tight to my BP/W at the waist strap. I can glance down and see it easily if my hands are occupied. I suppose I like it as streamlined as possible, so not over the shoulder. But if the hose length were perfect I could see routing it to the LPI hose for the BCD. Never thought about it, but it could also route with a dry suit hose.

I don't have enough experience to know whether the SPG or computer is more likely to fail, and I've not seen data on this. My 37.5 year old SPG still seems to work, though I don't dive it any more. The only computer failure that wasn't my fault was a pressure sensor going bad, giving me faulty depth. And that happened while driving home on a highway.

 

[VikingDives]

Yep. Same here. Batteries are cheap. I do preventive maintenance on my gear usually in January or February. The batteries in the transmitters get replaced at this point. This is generally well before they would be due for replacement, but it works for me, and the cost is well short of what it costs to actually dive.

I got 5 years on one MH-6a Battery. Until it failed... Now every year I replace it because I'd rather have it and not need it than need it and not have it.