SPG with AI computer?

[MaxBottomtime]

SP air 2 and a back mounted pony. No extras because they aren't needed.

You mentioned two items that are extras.

 

[Boarderguy]

You mentioned two items that are extras.

Not for my solo diving

 

[gamon]

I run a mini spg about the size of a nickel on a thin braided hose alongside my power inflator, so it's more like a "half a hose".

 

[MaxBottomtime]

Not for my solo diving

How often do you use a pony or Air2 during a solo dive?

 

[rfwoodvt]

Certainly there is benefit to redundancy for redundancy's sake. other times it's appropriate until the primary device has been certified to your satisfaction as not needing it.

I dove with a Suunto Vyper Air (I know not a lotta love or high marks for Suunto) and I loved it...no problems whatsoever with the transmitter. Until I tried using it while operating some of my underwater electronics.

Whenever I was running the UE my wireless connection was spotty and data erratic. I had intentionally carried an analog gauge with me as a matter of course because I added something new to the system (Wireless AI)

Anyhow, ai failed, no big deal I could continue the dive. Took a few dives to figure out the problem, trying different transmitters and computers.

Anyhow, all that to say, there is nothing wrong with redundancy in mission critical circumstances. It all depends on your style and temperment about such things.

I am of the camp whereby I expect most everything to fail at the worst possible time so I want a preplanned backup, whether it be redundant gear, or workaround solution/procedure when redundancy is not possible (like a drysuit)

Consequently I dive with a main ai computer and backup (which remains tucked out of the way) along with an octo on my main regulator/tank setup and complete independent air source. I dive a dual bladder bc as well even though I dive a drysuit.

Keep in mind, though, there is too much of a good thing. In my day job I climbed trees for a living. We had one guy, whom I hold in the highest regards in terms of safety and planning, but he insisted in triple redundancy all the time. Nothing wrong with that but it ended up costing him time and putting him in hazardous situations unintentionally.

Find the balance that works for you and let the wrath of the nay-sayers and the over-exhuberance of the preachers slide off your back.

 

[Boarderguy]

How often do you use a pony or Air2 during a solo dive?

Never had to, often for drills. Once with my buddy since I don't change my rig. Same gear means same drills.

 

[MidOH]

Keep the SPG in your SAD kit. It really is not needed on basic rec dives. IF, and that's a big IF, your computer/transmitter suffers a problem then you bail on that dive. Swap the SPG over during the SI and go diving on the next drop. I keep a PP2 in my SAD and the only brass & glass I have lives in my garage SAD kit.

Agreed. But being that the average dive Op only offers 10-14 dives in a weeks vacation, I may have just lost 10% of my vacation.

So I always have an Spg on my travel rig. May take it off for local stuff.

Or split the difference. Put the SPG on a short 24" hose so that it completely disappears on your waist d ring.

To be honest, brass and glass Spg's are cool. Snicker and laugh at the console divers.

 

[rmorgan]

My computer turns on when I hit the water, so the SPG is easier for verifying tank pressure when verifying the kit. Also for the rare occasion an operator wants ending pressure called out. And I had a transmitter battery fail awhile back. So, redundancy for us.

 

[inquis]

With some orientations of the first stage regulator, trying to run a second pressure "device" (SPG or transmitter) makes it apt to be smacked on a swim-through and should definitely be avoided. Whether you avoid angling the reg like that or forego the 2nd pressure device is up to your own priorities.

 

[Belzelbub]

If a SPG hose fails, it gets noticed. It is the unnoticed errors that kill.

Absolutely. I’ve seen both SPGs and transmitters fail. The transmitter failed on startup. A blinking red NO COMMS message is hard to miss. The failed SPG happened in the water, and was a bit more subtle. I was doing a dive that I’ve done many times, so had a pretty good idea of what the SPG should read. When I looked at it, it read higher than I expected. I continued for a few minutes, and checked a few more times. Needle was stuck. Flicked it a few times, and it finally resumed. This could have been worse on a more challenging dive, or if the diver didn’t have a good grasp on their air consumption.

An analog gauge is easier to understand when narced (I do have experience of this from 50m on air).

Yeah, probably. My computer displays both the number as well as a graphical representation of a tank. I usually use the numbers, but if they didn’t make sense, the tank graph would at least tell approximate pressure status.