Question about air integrated computers and transmitters

[JackD342]

I only use my computer, but I do have 2 of them at all times so I still have redundancy. As you're probably noticing, how much redundancy a given diver wants changes from person to person. On liveaboards, technical dives, etc, you'll find people tend to prefer more redundancy in things that could either impact their ability to keep diving (not knowing tissue loading would make doing the 5th dive of the day irresponsible so a backup computer is preferred by many for instance) or their ability to safely complete the dive.

When you are thinking through your considerations for possible redundancy, think of it in two ways:

1. What is my tolerance for missing or truncating a single dive based on an equipment failure?
2. What is my tolerance for sitting out 24 hours of dives if my sole computer fails before I can dive again with another borrowed or rented computer? THAT is the redundancy that is most important to me once I have spent time and money getting to a tropical destination.

 

[arcticat99]

i myself have been wondering about just going wireless .right now i use a analog spg but just rely on the computer for depth gauge .i had one dive where computer did not turn on when i jumped in .but just stuck with my dive buddy for depth ,as long as i could read my tank pressure i was good

 

[broncobowsher]

I have watched too many people have issues with AI to trust a whole trip on it. At least an analog backup in the spares. Would suck to be halfway through a trip and need to change batteries only to find the spare battery was a dud. Or any of the other random issues.

The gauge for a buddy to read is good as well. Many times I don't bother asking what pressure they are at, I just reach over and look. I have no issues if they do the same to me. I find it is smoother than asking what they are at. Clipped off under the arm is fine. Good way to find how good your instabuddy is of a diver and if they are tracking there own air without reminders.

As for redundant depth, before I ran multiple computers I never did. I had a forgot to turn on once on a non-water activated computer. Complete user error. I just stayed a couple feet above my buddy, had my analog pressure gauge, and called it after the first dive as I didn't have accurate log of the first dive. I got a better computer after that. Your buddy is the backup depth gauge. You will be at the same depth as they are. Don't be surprised at the computers not matching exactly, one may be set to salt water and the other for fresh, and there is a third calibration for European standards that is between the two.

 

[saxman242]

I, like many others, run an ai wrist computer and a small standalone spg. The spg is extremely useful for checking tank pressure when setting up gear, and with it clipped off to my hip d ring, never gets in the way. I've contemplated retiring it to my save a dive kit, but it's use during set up keeps me from doing so.

 

[Divectionist]

Perdix AI + small button SPG in first stage.

Button SPG more of a convenience for when I put the reg on to assemble the kit / check the gas in the shop before wearing my comp.

The AI appears to be perfectly reliable so far, and should it fail, I'd know within 10 bar where I am at and generally made a point to abort if the signal cannot be reestablished after 2 minutes.

To me this is safe and unlikely enough not to worry about an additional item dangling around that I am unlikely to ever look at.

Keep in mind this is for rec diving with an usual max depth of 20m. I would do it differently on deep wreck penetrations and the like.

 

[MargaritaMike]

I have two wrist AI computers. I carry a 2 spare transmitter , an SPG on HP hose, and a SPG / Depth console in my spares bag. I don't plan to lose a dive. I have 3 transmitters and have on occasion used two of them at the same time on a dive. So far, no problem with interference. If you don't have a problem with interference when you turn them on you "shouldn't" have a problem under water. YMMV

Cheers -

 

[CWK]

I started with an analogue SPG, then I purchased an AI computer and transmitter but kept the analogue SPG on my regulator. Eventually, after about 2 years of use in total, the high pressure hose developed a leak so I took it off. The high pressure hose has been replaced, but stays in my save a dive kit together with the analogue SPG.

 

[Jay]

... would there be a need for me to get an SPG/depth gauge with my reg kit?

... but I'm just wondering if it is common practice to not have gauges?

The main reason I'm wondering is because I am wondering if I should be more in the market for a transmitter instead of worrying about what gauges to get, and spending the money I would on gauges and put it towards a transmitter.

What works and feels right for one diver mayn't be the best fit for you but here's what I did and why:

I have AI with a small gauge attached my the 1st stage (pony size, larger than a button gauge). I have that because mostly where I dive it's 'full service' and the people to do gear setup like to have a way to verify they've attached a full tank. It's an extra failure point but that risk is extremely low. If things did go sideways with AI underwater, at least it's also some comfort for a buddy to know I'm not nearing empty by the time we get to the surface.

AI these days seems very reliable. From what I've gleaned on here the unreliability is a past issue. Therefore it seems to me most don't, but there was a recent poll that was interesting on the topic. Of those that use AI, 43% have an SPG. Of course, that doesn't tell us if the AI Computer / transmitter is newer/older etc.

Here's the poll: How do you dive?

and here's another relevant thread: Attaching AI transmitter to the 1st stage

 

[Seaweed Doc]

Interesting you should ask. I did my first 3 dives with my new transmitter and Perdix. It worked great for the first 2 dives but lost the connection in the middle of the third dive. But it reconnected toward the end of the dive. No idea why; dive 3 wasn't as deep as either of the first two. The computer battery is solid. Maybe an issue with the transmitter battery? Though I'm not sure why it would reconnect on its own

Regardless, I was glad I had an analog SPG, especially since I was the DM for the dive.

 

[Kamaros]

One of my buddies started having issues with the AI on his Teric, which was causing the pressure to jump around erratically. He had to get the transmitter replaced.

I personally dive with a Teric and transmitter of my own, but have a small SPG clipped to my hip D-ring DIR-style that I compare my Teric readings against several times a dive. I also bring my old computer (an Oceanic Geo 2.0) that I use as a backup computer/depth gauge.