Random question

[Ayisha]

...which means a single reg plus a crap "octupus" low-performances secondary stage.

You know, the octopus or backup doesn't need to be crappy. It can be a good, properly tuned reg.

 

[Nemrod]

You know, the octopus or backup doesn't need to be crappy. It can be a good, properly tuned reg.

I was going to say the same thing. I am not sure why it is so often stated that an "octopus" regulator will be crappy, non functional and full of dirt and never tested before or during a dive? But just to say, my wife has a Legend with a Legend octopus and the only difference is one has a yellow face and we do drills and she will breath it during safety stops to assure it works if needed. But, I guess it is just a crap regulator even though I seriously doubt there exists a regulator that breaths in any practical way much better than the AL Legend "octopus" second stage.

There are many ways to achieve (some or total) redundancy. In much of the world, at least in North America, most of the ABC agencies going back to NASDS and YMCA and LA County stress the Buddy System. Your buddy is your redundant air supply. Once a diver moves into solo or technical pursuits there are other considerations but for most open water divers trained in North America the Buddy System is the methodology taught and the Buddy System works. Other parts of the world may stress other means of achieving air sharing or redundancy or may not stress the Buddy System as the primary means of doing so, here in the USA, we do.

 

[Angelo Farina]

You know, the octopus or backup doesn't need to be crappy. It can be a good, properly tuned reg.

It should be a good reg properly tuned.
Unfortunately many octopus regs are tuned very hard for avoiding free flowing.
An adjustable second makes an excellent choice for an octopus, or any reg with a dive-predive switch.

 

[blueskies_up_ahead]

Even without doubles you can use a tank with two valves. Quite common here in Germany because the water is always cold below the thermocline. In many of the deeper lakes it's actually mandatory. So you have two independent first stages each with their own regulator. Those regs can be the exact same. No need for a lower quality octopus. If one of the first stages freezes, you can turn off the vale and still breathe from the other first stage. It's not a redundant air source, but a redundancy of first (and second) stages. Of course you could use the same regs with two bottles as well (connected or independent).

 

[DiveProKoko]

I am VERY new to scuba, 3 pool sessions deep to be exact.

Have a question about a failing air source. Would it be practical to run a double-tank setup and have a regulator for each tank? I'm assuming this would negate a reg failure on one tank allowing you to switch to the other one easily and without the need for an emergency situation. Maybe this is a stupid question? Just a random scenario I thought up whilst thinking about alternate source ascent drills...

For context a dive would be based on the capacity of one tank and essentially treating the other as a pony, but instead carrying a full 12L tank etc.

Practical, no. To set your mind at ease.....and I know there's going to someone who "knows somebody" and has a story to tell me how wrong I am.....but, regulator failures of well maintained regulators are nearly zero.