Disconnecting regulators underwater

[wetzjm01]

I posted this in the cave forum but also thought I would post it here in order to get more opinions.

I was talking to someone and he says that while cave diving if he carries more stage/deco bottles then he has regulators, he would actually disconnect the regs underwater and switch it to another tank that he would then use. Is this a common practice among cave divers with a lot of stage/deco bottles?

I was under the impression from Padi training that this was a big no no and could cause serious damage via dabree in the first stage. Another quick question, wouldnt this also cause water to enter your HP gauge and if so does it damage it?

Thanks in advance

 

[johnkendall]

I posted this in the cave forum but also thought I would post it here in order to get more opinions.

I was talking to someone and he says that while cave diving if he carries more stage/deco bottles then he has regulators, he would actually disconnect the regs underwater and switch it to another tank that he would then use. Is this a common practice among cave divers with a lot of stage/deco bottles?

I was under the impression from Padi training that this was a big no no and could cause serious damage via dabree in the first stage. Another quick question, wouldnt this also cause water to enter your HP gauge and if so does it damage it?

Thanks in advance

There are two parts to this question:

1 - Can you swap regs underwater
2 - Should you do it as part of a dive plan.

For 1, the answer, like many things, is "it depends". Many regulators will not mind too much having water in them, if the water is fresh (not salt) and it is cleared reasonably quickly. Piston regs tend to survive this better. You might be able to get water into the SPG, but it is unlikely.

For 2, I'd say this was foolish. While I might swap regulators around if I have a major failure on a dive with multiple stages, I wouldn't want to plan to do this, especially as I may have to do it gas sharing, in the dark (sometimes you have a *very* bad day)

HTH

John

 

[MSDT Mark]

There are two parts to this question:

1 - Can you swap regs underwater
2 - Should you do it as part of a dive plan.

For 1, the answer, like many things, is "it depends". Many regulators will not mind too much having water in them, if the water is fresh (not salt) and it is cleared reasonably quickly. Piston regs tend to survive this better. You might be able to get water into the SPG, but it is unlikely.

For 2, I'd say this was foolish. While I might swap regulators around if I have a major failure on a dive with multiple stages, I wouldn't want to plan to do this, especially as I may have to do it gas sharing, in the dark (sometimes you have a *very* bad day)

HTH

John

Well said...

 

[DA Aquamaster]

In my opinion it is something that should be done only in an emergency A freeflowing reg on a deco bottle is not really an issue that calls for switching the reg as you can manually operate the valve.

Swapping a reg underwater will mean water entering the first stage and that will mean the reg must be disassmbled, cleaned and dried. Regulators also vary in how well they tolerate this abuse. Some diaphragm designs are not meant to have non compressible fluids inside them and damage could occur. Water entering a diaphragm deco reg through a loose DIN connection on an upressurized deco reg can in fact be what causes the reg to fail in the first place. Consequently, diaphragm designs are not my first choice for stage or deco regs that are a carried pressurized but with the valve off during the dive.

Some piston designs have spaces inside them that are not "flow through" areas where water would be removed simply by passing gas through the regulator. And if not removed, corrosion will result.

In a cave swapping regs is one thing - although doing it in a silt out could be interesting, but swapping regs in an open water environment midwater in a current would in most cases be much harder.

With proper gas planning swapping a reg in the water is also not required as a technical diver should plan the dive in a manner that allows for the loss of 1 deco gas, relying on a combination of reserve back gas and the remaining deco gas, if two deco gasses were brought, or on the reserve back gas alone, if only one deco gas was brought. Reserve gas among the other team memebrs is an additonal redundant source of gas that may be available to carry out a deco with a missing deco gas.

Switching a reg during the dive would mean a delay on the bottom or at a deep stop where the entire team's deco schedule and/or gas planning will get screwed up while you dork around swapping a reg. The fact that you had a reg failure to deliver gas reg failure in the first place should require a hard look at how you are configuring yourself.

Planning to switch regs on stage bottles in a cave is indicitive of the diver not having enough regs in the first place for the dive he or she is planning. It also means that he or she will eb doing what amounts to an emergency procedure as a standard practice and is also betting a lot that the flooded, and possibly repeatedly flooded, reg will even work. If not, the diver is bascially hosed. It is one of the dumber ideas I have heard and ranks pretty high up there in the Darwin Awards nominations.

 

[b1gcountry]

I don't even dive with stages, and this still sounds like a terrible practice.

 

[VooDooGasMan]

Slowly put your mouth over the valve so not to have any water in the human first stage, Slowly crack the valve, inhale, close valve,exhale, Repeat for 1 or 2 hours of decompression.

COME-ON I do some stupid and dangerous stuff, But I depend on all my gear to be dependable and having all the right gear. If this fella (has'nt earned the cave diver name)
Wont purchase the right amount of regs, He wont service them properly or at all.

That practice was long ago, When I started Playing in caves they were extra tanks at deco stops. Cause you brought whatever gear you had to acomplish your dive.

Regs are every where and not that expensive.

There is no need for that diving practice, period.

There is no need to play that game, period.

 

[MonkSeal]

I did this once (no emergency) just to check if Apeks DS4 would work in this situation. It worked ok; I serviced it after dive. You realy have to have poor gas managment and many failures to be in situation to do this.

 

[rainman_02]

I posted this in the cave forum but also thought I would post it here in order to get more opinions.

I was talking to someone and he says that while cave diving if he carries more stage/deco bottles then he has regulators, he would actually disconnect the regs underwater and switch it to another tank that he would then use. Is this a common practice among cave divers with a lot of stage/deco bottles?

I was under the impression from Padi training that this was a big no no and could cause serious damage via dabree in the first stage. Another quick question, wouldnt this also cause water to enter your HP gauge and if so does it damage it?

Thanks in advance

The DIR answer is: yes, you can swap them underwater if you need to (emergency). It is NOT common practice to dive with more tanks than regs. That's just "farm animal stupid" to quote some people...




Can we consider this thread answered/closed yet?

 

[netmage]

I posted this in the cave forum but also thought I would post it here in order to get more opinions.

I was talking to someone and he says that while cave diving if he carries more stage/deco bottles then he has regulators, he would actually disconnect the regs underwater and switch it to another tank that he would then use. Is this a common practice among cave divers with a lot of stage/deco bottles?

I was under the impression from Padi training that this was a big no no and could cause serious damage via dabree in the first stage. Another quick question, wouldnt this also cause water to enter your HP gauge and if so does it damage it?

Thanks in advance

As others have posted... no, it is not a common practice... If your doing a dive that requires that many stages, get or borrow the gear to do it right...

The practice of keeping second stages finger tight has somewhat gone out of style. Some of the real explorers might still follow this practice, but I'm under the impression it is no longer being advocated in training...

-Tim

 

[DA Aquamaster]

The practice of keeping second stages finger tight has somewhat gone out of style. Some of the real explorers might still follow this practice, but I'm under the impression it is no longer being advocated in training...

I tried this for a short period of time based on "expert" advice and admittedly it did sound like a good idea. What I found was that for the first time in 15 years of diving I has having the o-ring in LP swivel portion of the hose fail, and fail on a regular basis.

This makes sense as if the second stage comes loose a couple of turns (not all that uncommon during a dive after s-drills, switching to a deco bottle, etc) the o-ring is then partially unsupported and can extrude, get pinched and eventually fail. I also found that this o-ring and the connection between LP hose and inlet fitting tended to be dirtier with this approach and the additional grit further accellerates o-ring wear. In the end, it was not worth it as it created a much larger problem than it could ever hope to solve. Realistically, a second stage failing to deliver air is extremely rare.

So if divers choose to leave their second stages finger tight, they will need to frequently check them to ensure they are remaining finger tight and they will probably find that they need to retighten them often. If a diver forsees the potential to have to swap second stages, it makes more sense to bring along a suitable tool to loosen the fitting and stow it in a pocket.