wireless computers

[fnfalman]

One argument that I see people make all the time against hoseless AI computers is that "you still need a backup in case it fails" or "if it fails you are so screwed." I don't get this logic at all. Why do you need a backup for a transmitter, but you don't need a backup SPG for your SPG? How is a transmitter failure on a hoseless AI computer any worse than a mechanical SPG failure?

Either way you no longer have a way to monitor your tank pressure. Either way you call the dive and ascend. If you don't have enough gas to make your ascent safely then you clearly weren't watching your tank pressure anyway, right?

Inevitably people answer that the transmitter is far more likely to fail. Is it really? Is that a fact or an assumption based on 'it's not mechanical' logic? Transmitters aren't mechanical, but they are solid state devices without moving parts. An SPG has moving parts and extra o-rings that can fail. Personally, I have experienced 2 mechanical SPG failures (both flooded and stopped giving correct info) during a dive and one transmitter failure (dead battery, but it told me it was low and I ignored it). I'm not claiming that transmitters are more reliable, but I would say that they are comparable in reliablity to a SPG.

If the features offered by hoseless AI computers are not worth the money to you then that's fine. Don't buy one. However, the idea that it is somehow less safe than a mechanical SPG is pretty lame.

Suunto just put out the HelO2 technical diving computer with air integration. I seriously doubt that Suunto would put out a product that might endanger a diver's life.

 

[fnfalman]

Also,

I wonder how many people that advocate a mechanical device's usage (SPG) also advocate the use of bottom timers that are reliant on electronics?

How many of these SPG advocates are also using mechanical watches as primary timing devices?

 

[Puffer Fish]

Also,

I wonder how many people that advocate a mechanical device's usage (SPG) also advocate the use of bottom timers that are reliant on electronics?

How many of these SPG advocates are also using mechanical watches as primary timing devices?

I think you are confusing the issue of questionable reliability with paranoia about technology. In the last 5 years, I've had 7 wireless transmitter failures at the point of diving (this included not working, having the battery suddenly go dead and one pairing event that was not fixable.) As I have a backup spg, none effected the dive or later dives.

During that same time, I've had a couple computer failures, but as I have a backup, that also did not effect any dives. Not counting any simple battery issues, as I have spare batteries.

But if you are using just the wireless for your pressure, then a computer failure is also a tank pressure failure, and your backup had better the same as your primary (which can be a bit pricey).

For computer backup, I carry one of three systems (depending on the diving). Liveaboard - second computer, as a computer failure will sit you down for a day. Single day diving in a place I don't know, a dive watch that records depth (solar powered). Single day diving to a known location, a mechanical dive watch (swiss, 2824 eta movement). And I have tables with me for just about any mix.

That is just under 900 dives, so my current view is that the wireless transmitter system is about 3.5 times more likely to fail than the computer is.

My current computer and transmitters just passed 200 dives, and they have yet to have a failure, so perhaps, I will change my concern over the wireless transmitter in another 300 dives or so.

 

[charlesml3]

I seriously doubt that Suunto would put out a product that might endanger a diver's life.

Neither would any other dive gear manufacturer.

 

[Supermanwoot]

I use an Aeris Elite T3, same as Oceanic VT3 with only slight differences in looks, but same guts.

I've never had a problem with mine. No lost signals, no dive-ending malfunctions, and no battery issues although it is VERY NEW.

I do worry about it getting older although I suppose that could be negated by proper maintenance and replacing the batteries before they get low!

 

[fnfalman]

I use an Aeris Elite T3, same as Oceanic VT3 with only slight differences in looks, but same guts.

I've never had a problem with mine. No lost signals, no dive-ending malfunctions, and no battery issues although it is VERY NEW.

I do worry about it getting older although I suppose that could be negated by proper maintenance and replacing the batteries before they get low!

I have the same thing. I had a problem with it gotten flooded in the battery compartment but that wasn't the computer's fault. Ineptness by the shop technician was the culprit. When he sealed the battery compartment, he didn't take proper care and the O-ring came off its position. Also, use good brand name batteries. Not all batteries are the same because the same tech was trying to save me money by selling me some no-name batteries (both computer & transmitter), and the damn things didn't transmit, couldn't receive, etc. Switched to Duracell/Energizer/Panasonic batteries and the computer & transmitter are currently very happy.

 

[Puffer Fish]

There is a very large variation in the functional design of Lithium batteries. It may not be cheap versus expensive, and some very good batteries are made by companies no one has heard of.

The issue usually is the maximum current draw capacity. CR2023's, for example, vary from around .4 to over 4 ma. If your computer needs (just as an example) 1.5ma to startup, then one with a maximum capacity of 1ma, will not work.

Your "find one that works" and stick with it, is an excellent plan.

Most diver computers are high load users (particularly on startup), versus say a watch, which is a small constant drain.

Sanyo and all the batteries you mentioned are high max current designs.

I have the same thing. I had a problem with it gotten flooded in the battery compartment but that wasn't the computer's fault. Ineptness by the shop technician was the culprit. When he sealed the battery compartment, he didn't take proper care and the O-ring came off its position. Also, use good brand name batteries. Not all batteries are the same because the same tech was trying to save me money by selling me some no-name batteries (both computer & transmitter), and the damn things didn't transmit, couldn't receive, etc. Switched to Duracell/Energizer/Panasonic batteries and the computer & transmitter are currently very happy.

 

[fnfalman]

There is a very large variation in the functional design of Lithium batteries. It may not be cheap versus expensive, and some very good batteries are made by companies no one has heard of.

The issue usually is the maximum current draw capacity. CR2023's, for example, vary from around .4 to over 4 ma. If your computer needs (just as an example) 1.5ma to startup, then one with a maximum capacity of 1ma, will not work.

Your "find one that works" and stick with it, is an excellent plan.

Most diver computers are high load users (particularly on startup), versus say a watch, which is a small constant drain.

Sanyo and all the batteries you mentioned are high max current designs.

Good to know. The problem is that the computer's operator manual doesn't tell you that kind of stuff. It just said use CR2023 (or whatever batteries).