The curious case of AI. Do you use a back up SPG while using AI?

[Divin'Papaw]

Same, I see so many people stressing about depressuring their regs to get the transmitter to shut off or not turning them on until the last minute etc. As an SPG user it's not something I stress about and my gear is often pressurized for hours before I actually splash (or after).

Same here. I set up my kit when I get on the boat and I leave it on the entire time until I’m breaking down at the end of the charter. I also leave charged for an hour or two when I’m soaking my regs. I find it ridiculous that people get so anal about their transmitter battery. The battery is not that expensive and it’s not that hard to change. I simply track approximately how many hours I have on a given battery and I replace it at about 50% of the anticipated life. I’ve never had a Transmitter nor a computer battery die on me.

 

[tursiops]

Same here. I set up my kit when I get on the boat and I leave it on the entire time until I’m breaking down at the end of the charter. I also leave charged for an hour or two when I’m soaking my regs. I find it ridiculous that people get so anal about their transmitter battery. The battery is not that expensive and it’s not that hard to change. I simply track approximately how many hours I have on a given battery and I replace it at about 50% of the anticipated life. I’ve never had a Transmitter nor a computer battery die on me.

Especially since many computers will tell you the state of your transmitter battery, which is encoded (at least for the PPS transmitters) in the signal received by the computer.

 

[dmaziuk]

What about get connected to the divers you're guiding? What do you think of that, to be able to read out their levels?
In the poolbusiness everything goes to bluetooth connecting and wifi, but this also comes with a lot of troubles. Takes a lot of time to convince people it's not that stable as wired connections.

Radio doesn't work underwater. As in, for distances longer than from your shoulder to your wrist, you're looking at kilometer-long antennae and nuclear reactors to power them. Ultrasound has better range but so far every vendor who tried it has gone extinct. Except Garmin, but they only just started (and it's far from being their main product anyway).

 

[amado_sarhan]

Same, I see so many people stressing about depressuring their regs to get the transmitter to shut off or not turning them on until the last minute etc. As an SPG user it's not something I stress about and my gear is often pressurized for hours before I actually splash (or after).

Thanks for sharing this! I have to say this comes down to habit. I've only been using SPGs all my life, but I immediatly depressurise right after a dive and make sure that the SPG reads zero.

 

[J-Vo]

That sounds like a lot of hose failures. Which brings me to 3 questions:

1) Miflex or rubber?
2) How many dives?
3) Are they bent like SPGs on a stage?

Edit:
And 4) Were they all old hoses that just happened to all die in the same year, or are they around a year old?

I'm having trouble with new rubber hoses from DGX. Several of them have had micro leaks out of the box. Slow enough to hold pressure over 24 hours when staged, but you can see the bubbles on the hose. Just had one completely die on an O2 tank I had staged in Ginnie, fine one day champagning bubbles the entire length of the hose when I checked it the next day. These are all 6 or 9" rubber hoses with no bends.

 

[boriss]

Everything fails, what you do should depend on your mission, type of diving you do, your own philosophy/gear, etc. I'll bet most respondents in this thread are planning their dives so well, in theory they could dive without a gauge at all.

For stage/deco bottles I prefer SPG (they're handled poorly, I'd be afraid to break a transmitter and when I leave a bottle somewhere, I don't want to care about a battery running down). For back-mount doubles transmitter on right post, SPG on the left. For CCR transmitter on DIL, SPG on O2.

 

[SlugLife]

There are probably 50-dozen threads on this exact topic. A few examples:

Spg, AI, both

Had a discussion with my instructor wether AI alone is safe enough or not I believe they are enough in them self he believes you have to have a spg and a transmitter. Got my curious what a peoples preference and why

scubaboard.com

SPG with AI computer?

So I recently picked up a like-new Oceanic Atom 3.1 and transmitter, which looks like they've never even been used. Tested the air integration out on a tank at my local dive shop, and it seems to work fine. My wife and I will be further checking out all our scuba equipment in their pool prior...

scubaboard.com

AI & SPG?

For those of you that dive with an AI computer, do you still use an SPG in case the computer stops working on you dive? Just curious...

scubaboard.com

Anyway, I also have a SPG on a short-hose (sidemount), simply because it makes checking tank pressure before a dive much easier, without using my dive-computer.

I also happened to use the SPG once when I started a 30ft dive with a dead computer-battery. I might not normally recommend doing that, but it was a 30ft dive, by the shore, in a familiar location, and I had plenty of redundancy with me. So I technically have used the SPG on a dive once, but I was 30 seconds from the boat and could have swapped the battery (or checked my computer before the dive).

 

[InWay2Deep]

Just curious, was it a swift or the older model? I had that happen with a swift a few weeks ago...

It was a SWIFT, just shy of a year old.

 

[stuartv]

I use transmitters on everything except deco/bailout bottles.

Dil and O2 on CCR, sidemount cylinders, backmount doubles, and single tank - all have transmitters. That covers anything from shallow, single tank OC to 100m ocean dives to cave dives.

Deco/bailout regs have button gauges.

I'm closing in on 800 dives with AI, all using the PPS transmitters (no Swifts), and never missed a dive or had one cut short because of an AI problem.

I teach for a shop that is a Shearwater and also Oceanic dealer. I can get Swift transmitters at dealer cost. I just bought a couple of new transmitters. I bought Oceanic, rather than a Swift at the same price. The need to have a small hex wrench to the change the battery on a Swift will have me continuing to buy the older style for as long as I can still get them (which is probably indefinitely, since Oceanic and Aqualung still use them for their AI computers).

Love the new Petrel 3 with AI, I remember years ago when the Perdix first came out with transmitter capability and I was thinking how cool would it be if you could get your transmitter read out on a hardwired Petrel.

The controller on the X CCR offers that. It has hard wiring from the dil and O2 1st stages to support showing those cylinder pressures on the controller's display.

My last computer did not show the transmitter battery status, so failure or premature replacement was the only options. I had a good battery replacement process, but one battery did not last like the others. SPG allowed us to continue the dive and replace battery at SI.

All the AI computers I have had did not show the transmitter battery status - until the battery status was "low", then they will show that. In my experience, that is always enough warning to do at least one full dive (and probably one full day of diving) before the transmitter battery dies. I keep a spare transmitter battery in my reg bag. There is no good reason for a transmitter battery being dead to be the reason a dive has to be aborted. At least, not with the PPS (MH8A) transmitters.

What computer and transmitter did you have that did not show transmitter battery status?

Having a transmitter AND an SPG on the same reg set is just doubling your chance of a failure (for no good reason).

 

[scubadada]

I have had 2 transmitter failures, both Oceanic MH8A, since 2010. I have dived an Oceanic VT3 since 2010. I added a 2nd AI, a Shearwater Teric in 2019 to replace my non-AI backup and run it off the same transmitter as the VT3. I have a SPG on my other HP port.

My first transmitter failure was in 2017 after 865 dives, some kind of hardware failure. My second transmitter failure was in 2022 after 875 dives, failure of the over pressure valve. Both transmitters were replaced through the Oceanic Services program for $120 each. I started taking a spare transmitter on dive trips or have it at home in Florida.

I have never missed part of a dive, a dive, or a series of dives due to computer or transmitter failure. For those of you who know me, I have had my share of potentially dive ending problems with my Teric, black screen and antenna failures.