Switching regs from one cylinder to another U/W?

[TomZ]

I understand you should never run out of gas. You should always have a buddy who has gas. But.....

If for some unforeseen reason, i.e. catastrophic redundant failure occurs can it be done? While underwater, can you safely/effectively remove a regulator from one cylinder and put it on another cylinder and be able to safely breathe? if so, what are the consequences to the regulator? What servicing would need to be done?

For example, your buddy gets trapped at depth, you have extra cylinders in the boat, but no spare regs. Time is of the essence, and you determine the extra time in switching cylinders on your gear is a bad choice.

Or you have a failure of your deco bottle reg and have to use your primary reg set.

I've just finished PADI Rescue, and "what if's" are occurring to me. Thanks for your input.

 

[nimoh]

from this thread, it sounds like it is possible.

http://www.scubaboard.com/forums/basic-scuba-discussions/154351-changing-tanks-underwater.html

 

[g1138]

It should be very possible unless there's a lot of fine grit in the water that can get through the first stage filter.
The air pressure from the tank should be able to purge all the water from the first stage. You may get some water in your HP hose/SPG and your first breath may be moist or wet, but you should still be able to breath from it with little to no difficulty I'd like to think.

A full disassembly, cleaning, and reassembly would be in order after that IMO.

 

[TSandM]

I know someone who was on a dive where a deco reg blew up, and the diver switched regs. The regs have to be serviced, and the SPG is toast, but you can do it.

 

[DevonDiver]

It's a known technique in technical diving. I actually teach this technique as part of the new PADI Tec Sidemount course syllabus:

 

[Searcaigh]

As DD said above, and as also mentioned the reg that is used for the exchange is serviced before use again.

 

[dwhthediver]

Aqualung regs with the acd should stay dry and save the SPG. I would still service it after the dive.

 

[PfcAJ]

It's possible, I've had to do it once. I dot recommend doing it for grins, though.

 

[Rich Keller]

It can be done as stated above. You can also breath directly from the tank valve without a reg.

 

[Jim Lapenta]

Aqualung regs with the acd should stay dry and save the SPG. I would still service it after the dive.

Actually they will not. Neither will the Oceanic DVT system. They are only designed to stay closed at a minimal amount of pressure such as would be encountered by accidentally dropping it in a rinse tank. Anything deeper than say three feet or so and you will get water in them. Switch regs under water and you will still trap water between the reg and tank that you will then blow into the first stage, spg, and second.

But as to can it be done? Absolutely. We did this in the Disaster Scenario workshop we did with Steve Lewis (Doppler here on the board) at Dutch Springs. He had a HOG D2 first stage with a HOG second with no spg to ruin. There were I believe 7 of us that actually did the exercise. The first two breaths were a little wet but after that no water. It will definitely require a service after as even fresh water has minerals that if left to dry and set around will junk up the first stage.