Underwater reg swaps?

[northernone]

Basic question but regarding multiple cylinders diving.

Have you switched regs between tanks underwater?

Planning: What circumstances would have you decide that was the best course of action towards safely returning to the surface?

Dive execution: What potential risk factors do you see?

Post dive: In salt water are we fairly certain the SPGs would be salvageable? A good soak for the first stage itself, or is a rebuilt the minimum after forcing a few cc of salt water through it?

I've had 4 dives with decompression obligations where I considered switching out a regulator to gain access to the unused gas: 1. Blown hp hose oring. 2. An instructors deco bottle DIN oring blew. 3. A drowned deco rebreather I had hard plumbed to an o2 bottle had me left with extended air deco. 4. A badly torn mouthpiece and a metal reg made breathing wet or uncomfortable. (Not a golden retriever nor possessing other birding breed genes).

Each time contingency gas reserves were sufficient to sustain the total gas loss without incident. However, it would have been nice to once again regain a redundancy in case of further failures and also add extra conservative with an extended safety stop.

This was pondered with a 45 minute air deco obligation while my instructor had a full o2 bottle rendered inaccessible by 20 cents of vitron. (He rejected the offer to buddy breath or share my o2 as conditions were conducive for extending the dive. I stuck with him on o2 for solidarity)

Well, that's that.
Cameron

P.s. I am confident some of you have had X number of divers over Y years and due to Z training or L brand or Q maintenance schedule or P deity have never experienced a situation where this might be even a consideration. For you, I am glad and happy you've not had dive plans modified due to such issues.

 

[TrimixToo]

I did this once when I had a deco reg free flow. Feathering the valve was not working out. My choice was 15-20 minutes of "valve on, inhale, valve off" drill, adding something like 30 minutes to my deco, or switching regs. There was really no added risk. I was in fresh water, above the thermocline (warm!), had plenty of back gas with which to complete deco in case it did not work out, was quickly getting tired of the valve drill, and decided to try switching regs. It worked fine. I cleaned both first stages afterward. It was not at all obvious why the free-flowing reg did so when I took it apart. I put it back together with its second new seat of the year and it worked fine; none of my regs have free flowed since then. Gremlins, I guess.

In salt water, I'd have done the on/off drill until done. If things had already gone pear-shaped and I needed the gas to ascend safely, though, I'd switch regs in a heartbeat and worry about salt damage later.

 

[rhwestfall]

Thankfully, I've never had to, but I believe in "gear is disposable, life is not". Curious to see where this discussion goes.

 

[kelemvor]

Last June in Marathon, I watched someone change the o-ring on a yoke valve underwater. He then replaced the reg on the tank and finished his dive with it.

I would imagine you just have to break it down and fully service the reg in order to get the salt out of it...

 

[oldschoolto]

Swapping regulators underwater is not a big deal... I was reading a thread about a diver testing a regulator set for a company and had swapped it with flooding underwater a few times as per testing and he said the set was "FINE"..

As a rule, What ever you need to do to safely end the dive is far game.. If that means flooding a regulator to get to breathable gas, That's what I'm doing.. Best case is a simple rebuild.. Worst case is new regulator set..

Jim...

 

[RyanT]

Swaping out regs underwater would pretty much be my last choice. I would prefer to buddy breathe or feather a valve. But, if those options were not available/working, I would swap regs and worry about the salt water intrusion later.

 

[Diver-Drex]

I would consider both SPGs scrap. On the one you're removing the water would have a long way to travel to get to into the SPG, but why take the chance.
Soaking the 1st stages wouldn't do anything to clean the internals. They would need to be disassembled and cleaned. Again, maybe one would be ok but $30 in parts and an hour to rebuild is no big deal.
For risks:
- o ring damage during the swap, more a concern with a yoke reg
- forcing debris into the first stage resulting in two bad regs
- dropping the functioning reg during the swap, make sure the 2nd is clipped off

- D

 

[Doby45]

If it saves your life, screw the SPG and simply rebuild the first stage. SPG $50 + Rebuild Kit $20 = $70 to live. Works for me.

 

[PfcAJ]

I've done it. No ill affects. Always fresh water. Blow out the water post dive and git on wit it.

 

[Rusty Shackleford]

This only works on a piston first? Or not?