Does everyone really need an SPG? (w/transmitter)

[Mudakdivers]

which dive computer?

I believe it was an older Sunto.

 

[wetb4igetinthewater]

I believe it was an older Sunto.

Well that's just asking for it!

 

[divad]

If you've installed an air pressure transmitter that shows you remaining pressure on your dive computer, do you really need the hose SPG?

Yes.

 

[J-Vo]

I've read a few comments about batteries running out during dives. I don't think you can blame this on the technology.

When I was using Oceanic PDCs the manual clearly stated the TX batteries are designed to last longer then the PDC battery, and recommended always changing both at the same time. RTFM folks.

 

[kelemvor]

If you've installed an air pressure transmitter that shows you remaining pressure on your dive computer, do you really need the hose SPG?

Sure, if the transmitter or computer malfunctioned, you needn't end the dive because the spg is there.

But to retain the spg in the unlikely event of a malfunctioning transmitter and be able to continue that dive?

You'd bring and store your spg and of the transmitter malfunctions, it takes a movie with a wrench between dives to connect.

Or are there other reasons to have the spg?

Outside of technical diving, I think the honest answer is no. I ditched the redundant spg a couple years ago. It's easy enough to end the dive in the unlikely event of a malfunction. Just as you would have to do in the unlikely event of a malfunctioning spg if that were your only method to measure tank pressure.

I'm sure as time goes on, fewer and fewer will want to bring a redundant gauge.

 

[CosbySweater]

I've read a few comments about batteries running out during dives. I don't think you can blame this on the technology.

When I was using Oceanic PDCs the manual clearly stated the TX batteries are designed to last longer then the PDC battery, and recommended always changing both at the same time. RTFM folks.

You might not "blame" it on the tech, but that issue is inherent to the tech. SPGs have their own inherent issues. That's why many divers dive with redundant systems - to reduce the likely hood that the inoperability of one system would cause you to abort your dive, or worse. For all the BS that's been spat of this thread I've not heard one good reason why you absolutely should avoid carrying a redundant air supply measuring device, whether you have an AI or not. Plenty of reasons for carrying it, though......

 

[wetb4igetinthewater]

You might not "blame" it on the tech, but that issue is inherent to the tech. SPGs have their own inherent issues. That's why many divers dive with redundant systems - to reduce the likely hood that the inoperability of one system would cause you to abort your dive, or worse. For all the BS that's been spat of this thread I've not heard one good reason why you absolutely should avoid carrying a redundant air supply measuring device, whether you have an AI or not. Plenty of reasons for carrying it, though......

Well, in the time I've had a Perdix AI, I've had 2 SPGs fail, stuck during dives.

For recreational diving where I'm taking pictures, I'm in sidemount, have transmitters on both my cylinders and no SPG. I can check my cylinder pressures with just looking at my wrist and I never let go of my camera with either hand.

I could in sidemount have both an SPG and a transmitter, but that's kind of an ugly setup (my opinion).

Now for technical diving, there's no camera. I'll just conform and have SPGs instead of transmitters. For technical diving, I'm big on matching gear as much as possible.

 

[Bruce_Partridge]

I have a question. Over the years I have had a couple of SPGs fail. Both of them failed by not going all the way back to 0. It's not hard to detect by just paying attention when you take your gauges off, but I wonder if that is a common failure mode.

 

[Belzelbub]

I have a question. Over the years I have had a couple of SPGs fail. Both of them failed by not going all the way back to 0. It's not hard to detect by just paying attention when you take your gauges off, but I wonder if that is a common failure mode.

I’ve never seen that behavior with mine. PPS transmitter with Oceanic VT 4.1 and now with a Perdix AI. I usually do watch the pressure reduce to zero after I turn off the gas and purge the lines.

Edit: Oops. Read that as transmitters, not SPGs. Disregard.

 

[wetb4igetinthewater]

I have a question. Over the years I have had a couple of SPGs fail. Both of them failed by not going all the way back to 0. It's not hard to detect by just paying attention when you take your gauges off, but I wonder if that is a common failure mode.

The two SPGs that I had fail, failed mid dive stuck at a different value each. I noticed it within a couple minutes as I saw that "hey, the needle didn't move". My transmitters were both working (ugly to have both an SPG and transmitter), so I did keep diving (solo, photography).