Is an SPG necessary with a wireless computer?

[gypsyjim]

Possibly I should have used the word redundant, rather than fail safe?

Today it is standard to have an alternate air source (back up regulator, etc) on us, which is no where near as streamlined as our single regulator, no SPG hose or console of the early days of diving, but both are dam-sure-welcome additions, IMO.

Redundancy for additional safety and as streamlined as possible. A balance.







/

 

[Dive-aholic]

SPGs fail too. They can stick, they can flood, some little piece of crud can get in the teeny tiny hole and stop them from reading. I guess you'd better get two just in case.

Every piece of equipment can fail. As long as you understand what can happen and what to do if it happens, there shouldn't be an emergency.

Yes, SPGs can fail. I've just never seen it happen. I've had one flood and it still worked. I replaced it after that dive. I've seen transmittors fail several times.

 

[ddmattos]

Just keep the SPG on a short hose (try 24") clipped with a SS bolt snap to your left D-Ring. Hopefully you will never need it, but it saved a few dives for me.
*I have lost signal two times in high magnetic areas. Weird but it was strong enough to throw my compass off.
*I have had the PSI get stuck once on a dive in Greece. Only happened once. But didn't have to cut the dive short thanks to the SPG.
*Great for checking PSI in tanks without starting your dive computer.

I love my transmitter and find them extremely reliable, but the SPG has payed for itself in the few dives when needed.

 

[flots am]

I'm streamlining my kit, have just got a Vyper Air. I'm now thinking 'Can I lose the SGP hose?' I don't plan to dive much beyond 20m - How reliable are the transmitters?

If you're doing recreational no-deco dives, you can absolutely ditch your pressure gauge in exchange for the computer.

If your computer fails, all you need to do is end the dive normally. If your computer fails a lot, you need to send it back for repair or replacement.

flots.

 

[randy88k5]

I dive with a wireless transmitter, but I do have a SPG clipped off as a backup. One thing I found is when you are using a DPV, there is too much electromagnetic interference for the wireless to work. You have to stop the DPV to get the signal. I know how much air I use and what depth I was at, so no big deal. If I was really concerned, I could have held the SPG in one hand to watch the air usage. I would definitely recommend both if you have the room, available ports, and can do it in a streamlined manner. This is assuming you are going to use the wireless unit regardless.

 

[charlesml3]

It's a useful tool, but it isn't a necessity.

It sure isn't. When started diving in the late 70's there were no gauges at ALL. We used a stupid J-Valve that would slowly pinch off your air supply at somewhere around 500psi to let you know you were getting low on air. I managed to make plenty of dives safely with that.

I'm honestly surprised we didn't get a "You're gonna die if..." quote somewhere in this thread. Someone even said you should keep the SPG because the battery in the transmitter might die. That's a reason to CHANGE YOUR BATTERY, not add another gauge. That makes as much sense as bolting another tank on your car because you "might run out of gasoline."

There are always these stories running around with anecdotal evidence that AI computers are "prone to failure" or "unreliable" but I can never find any data to support the conclusions. In my years of diving I've seen more SPG's fail (2) than computers (1). I usually ask for details when someone reports a failed computer and the majority of those were Dead battery (your fault, not the computer), and flooded (again, your fault for not replacing the battery door O-ring properly). Did find one that failed due to a manufacturing defect that allowed water to seep in around the button O-ring.

Anyway, if my computer died during a dive I'm going to react according to the situation. If it's a nice, easy, clear dive in Cozumel I'm going to move closer to my buddy or group and let the DM know my gauge has died and then I'm going to continue the dive. Yes, you read that right. I know my consumption and I know I'm safe enough to go on and come up with the group.

If it's a fast current, deep, or murky then the situation changes and I'm going to make a different decision. Either way, I'm unlikely to die because my gauge or computer quit.

-Charles

 

[Atom]

I dive with a wireless transmitter, but I do have a SPG clipped off as a backup. One thing I found is when you are using a DPV, there is too much electromagnetic interference for the wireless to work. You have to stop the DPV to get the signal. I know how much air I use and what depth I was at, so no big deal. If I was really concerned, I could have held the SPG in one hand to watch the air usage. I would definitely recommend both if you have the room, available ports, and can do it in a streamlined manner. This is assuming you are going to use the wireless unit regardless.

Guess it depends which one. I have a Cuda 650, I used it on dives with the transmitter, worked like a charm. YMMV.

I still favor an SPG (not a console, only the SPG) clipped to the left d-ring.

 

[AnakChan]

Sorry for necro-posting but this topic was actually of interest to me in the past few days when I received my new reg (no oct, no SPG). I also owned D9 for the past 5 years and both, including transmitter, had their batteries were replaced last month. 4 days ago I took my new reg to the shop to have transmitter installed and tested briefly and it worked.

Today at the 1st dive prep, and 1st dive it also worked but in preparation for the 2nd dive, I couldn't get the transmitter to sync to the D9. Set the watch back to Time mode, then back to Dive mode, and resetting the transmitter didn't work. Luckily we were doing just extremely shallow beach dives so I just had to buddy up with the DM close by.

A backup SPG is highly recommended and I'll be sourcing one real soon.

 

[Doc Harry]

If you had a GPS in the wildenress, would you do without a paper map?

 

[AnakChan]

Not too sure if that's a comparable analogy since a GPS just gives coordinates with no referential data. Anyhow, reading on all the posts here, there doesn't appear to be a 100% agreement that SPGs are a must - having said that I do fall into the SPG is a valuable backup camp.