Question Should I replace my SPG with my new Shearwater Transmitter?

[Wheeler925]

I have had 2 transmitter failures in 300 dives. I was not big deal as I had my transmitter but also the SPG (although on the first failure I had to abord the dive as it was leaking). I would not have only the transmitter but for me it is not a problem to have the transmitter and the SPG. The transmitter does thing the SPG cannot do.

How did the transmitter(s) fail, and what brand?

 

[tursiops]

I have had 2 transmitter failures in 300 dives. I was not big deal as I had my transmitter but also the SPG (although on the first failure I had to abord the dive as it was leaking). I would not have only the transmitter but for me it is not a problem to have the transmitter and the SPG. The transmitter does thing the SPG cannot do.

What brand transmitter? Was it a battery issue?

Oops, redundant to previous post.

 

[Pearlman]

I’m not sure I understand why keeping the SPG as part of your standard equipment configuration feels cumbersome or a burden of sorts - not like it’s a gigantic grandfather clock one is carrying that upsets one’s weight and buoyancy calculations. It is small and compact enough to tuck in to one side… I use both and often check my SPG immediately after reading the pressure off my transmitter - just to keep my muscle memory and also compare accuracy of each device - typically the SPG reads 3-4 bar more compared to the AI transmitter. Knowing how my devices behave over time and having relative reference data points gives me a feeling of trust about the state of my gear.

On my last dive vacation, I found my Transmitter battery had died and so I used only the SPG the first few days until I got the battery replaced. But the DC had paired with the transmitter on the boat on the 1st day just before the 1st dive, and only when I commenced the dive that I realised I had a non-functional device - perhaps I did not look properly for low battery warnings … anyways while this was the first dive of my vacation with the dive shop, a group of tourists who were instructors in their home country had already been diving a few days with them and so the first dive of that day was a moderately difficult-level (considering tropical warm water conditions) deep channel dive in the Maldives. Needless to say it was a “high effort” dive in terms of navigating strong currents, and staying together with the group, where we took the entire first 10 minutes of the descent to find our way to a suitable spot on the cliffs edge of the channel and deploy our reef hooks. And then practically everyone was low on air at 35 mins into the dive. Having the SPG as a backup device meant I didn’t start excessively worrying or start panicking about having to abort the dive in strong currents during a period everyone was basically fending for themselves while navigating the currents and racing to a safe spot the dive leader was scanning for on the channels ledge. I took delight in the moment I told myself that it didn’t matter - thanks to my backup SPG, I could continue as if nothing had happened. We saw something like 30-40 gray reef sharks swimming around over the channel and ledge, on that dive. Talk about the peace of mind that being suitably prepared brings…

This thread really needs a poll:
Q: Do you use both AI and SPG on your dives?
Option1: No I leave my grandfather-clock sized SPG on the boat
Option2: Yes I dive with both my compact miniature SPG and AI transmitter at all times…

Anything else doesn’t make sense to me …

PS: Use a small 3” SPG not the larger two-dial models with hard plastic boot that can feel klunky and cumbersome…

 

[Divin'Papaw]

I’m not sure I understand why keeping the SPG as part of your standard equipment configuration feels cumbersome or a burden of sorts - not like it’s a gigantic grandfather clock one is carrying that upsets one’s weight and buoyancy calculations. It is small and compact enough to tuck in to one side… I use both and often check my SPG immediately after reading the pressure off my transmitter - just to keep my muscle memory and also compare accuracy of each device - typically the SPG reads 3-4 bar more compared to the AI transmitter. Knowing how my devices behave over time and having relative reference data points gives me a feeling of trust about the state of my gear.

On my last dive vacation, I found my Transmitter battery had died and so I used only the SPG the first few days until I got the battery replaced. But the DC had paired with the transmitter on the boat on the 1st day just before the 1st dive, and only when I commenced the dive that I realised I had a non-functional device - perhaps I did not look properly for low battery warnings … anyways while this was the first dive of my vacation with the dive shop, a group of tourists who were instructors in their home country had already been diving a few days with them and so the first dive of that day was a moderately difficult-level (considering tropical warm water conditions) deep channel dive in the Maldives. Needless to say it was a “high effort” dive in terms of navigating strong currents, and staying together with the group, where we took the entire first 10 minutes of the descent to find our way to a suitable spot on the cliffs edge of the channel and deploy our reef hooks. And then practically everyone was low on air at 35 mins into the dive. Having the SPG as a backup device meant I didn’t start excessively worrying or start panicking about having to abort the dive in strong currents during a period everyone was basically fending for themselves while navigating the currents and racing to a safe spot the dive leader was scanning for on the channels ledge. I took delight in the moment I told myself that it didn’t matter - thanks to my backup SPG, I could continue as if nothing had happened. We saw something like 30-40 gray reef sharks swimming around over the channel and ledge, on that dive. Talk about the peace of mind that being suitably prepared brings…

This thread really needs a poll:
Q: Do you use both AI and SPG on your dives?
Option1: No I leave my grandfather-clock sized SPG on the boat
Option2: Yes I dive with both my compact miniature SPG and AI transmitter at all times…

Anything else doesn’t make sense to me …

PS: Use a small 3” SPG not the larger two-dial models with hard plastic boot that can feel klunky and cumbersome…

See my first post. One of those linked threads already has a poll.

As to why?

1. One less hose with o-rings and a mechanical device that can fail
2. I find my reg easier to manage off of the tank. Minimal but noticeable.
3. I didn’t dive with two SPGs before adding AI. Why would I now need redundant pressure measuring devices?

It comes down ultimately to preference.

 

[KenE]

This comes down to a preference. In your case, you don't have a choice. The transmitter, via computer, will provide more information than a standard SPG. So, it is a very easy decision to run the transmitter instead of the SPG. Some run one or the other and some run both. We can argue/discuss indefinitely, but it comes down to a preference and buddy/team decision. I run both, SPG on shorter hose over left shoulder with inflator hose, out of the way and check it only occasionally. Transmitter on short hose just behind right shoulder with computer on right hand. Seems to work for me and the group I dive with, so no need to remove the SPG. If I had to decide which to run if only one, it would be the transmitter.

 

[scubadada]

See my first post. One of those linked threads already has a poll.

As to why?

1. One less hose with o-rings and a mechanical device that can fail
2. I find my reg easier to manage off of the tank. Minimal but noticeable.
3. I didn’t dive with two SPGs before adding AI. Why would I now need redundant pressure measuring devices?

It comes down ultimately to preference.

You dive local dives in SE FL that you are very familiar with. As I know too, it would be no problem finishing off a dive and being secure that you have enough gas. I dive many sites that are new and challenging (Malpelo, Revillagigedos...). I would not necessarily feel secure continuing a dive under these circumstances if I did not know my gas supply. This has come up for me on a couple of occasions. I will dive with a backup SPG and you will not. As you said, personal choice.