How great is the risk (in your perception)?

[Dan_P]

@Akimbo yet, pSCRs are still in relatively wide use.

On that note, I doubt that large-scaling the JYC approach to diving O/C would be considered anywhere near "safe".

As for the capacity to measure exact pp02, or rather the inability to, I believe we're starting to approximate a crude reasoning behing COPIS employment...

 

[Capt Jim Wyatt]

Many many CCR divers subscribe to the team bailout concep, so calling it nonsense, is nonsense.

 

[PfcAJ]

Many many CCR divers subscribe to the team bailout concep, so calling it nonsense, is nonsense.

Many people do all kinds of dumb stuff.

It's still dumb.

 

[Gareth J]

This was true when I was diving a j-valve and no SPG. It's definitely far more passive than CCR, but you still have to pay effin attention.

I don't disagree. The primary point is that OC gives direct indication that all is ok, or you have an issue.
A regulator works, or doesn't. You have gas, or you don't. Etc

CCR's can fail, and they appear OK for some time afterwards, you may not actually realise that there is a problem if you are not monitoring the unit. i.e. Solenoid failure resulting in falling PO2! A lot of issues on CCR are insidious. The upside, as I said, is if you are paying attention, you have time on your side.

 

[Capt Jim Wyatt]

It's still dumb.

Opinions vary.

 

[PfcAJ]

Opinions vary.

It would be similar to a cave diver in a team of 3 thinking it's ok to dive to halfs so long as the others dive to thirds.

Sound preposterous?

It is.

 

[The Chairman]

It would be similar

No. No, it wouldn't. One of the joys of rebreathering is reducing the total amount of gas you have to carry. Divers have developed strategies to maximize that. You may not understand them or ever utilize them, but comparing it to another strategy seems disingenuous.

 

[PfcAJ]

No. No, it wouldn't. One of the joys of rebreathering is reducing the total amount of gas you have to carry. Divers have developed strategies to maximize that. You may not understand them or ever utilize them, but comparing it to another strategy seems disingenuous.

It really would. Diver A needs less gas since divers B and C can cover him if things go sideways.

I understand rebreathers and utilize them.

Reducing the amount of gas you carry to levels where you can't survive a single failure without help from someone else is baloney. I'm shocked (jk not really) that so many people support such an idea.

 

[Gareth J]

On the subject of team bailout. I have seen it used both with OC and CCR.

When I was doing a lot of ERD and Mix gas diving on the South Coast. The group I dived with always put a trapeze in. We all carried sufficient gas for independent diving. The general rule, was plan for either a travel or a decompression gas failure, and be able to make a safe ascent to the surface. Losing both travel and decompression gas was a KYAGB (Kiss Your Ass Good Bye).
That said, the trapeze ALWAYS had a spare travel and decompression gas clipped in.
Because we dived on a trapeze, we ALL had to ascend the shot, run times where such that we would all be on the trapeze at a similar time. Even though we carried our own gas, we could swap out cylinders with others in the group. If we could get a diver to the trapeze, there would be gas. In addition, divers finishing their decompression could leave additional gas with the diver in trouble if required.
Whilst this isn't strictly team diving, the availability of gas was very similar.

When I did my final Mixed Gas CCR qualifying dive, it was a team dive, 6 of us. A full bailout at the end of the bottom phase of the dive would require 1.5 travel gas cylinders, and two decompression gas cylinders. So, from the plan we had the capability to safely exit two divers on 100% bailout. In addition, an exiting CCR diver could always return with additional gas (or his rebreather) at the end of their decompression phase. To have done the dive with out team bailout would have required each of us to carry two Ali80's of travel, and two Ali80's of decompression gas.

Much of my recent dive has been more recreational, i.e. no deeper than 40-50m, decompression under 30 minutes. I can carry my own gas for this. Often I am diving with OC buddies, so I am carrying additional gas for them if we get into real trouble. I very seldom dive with buddies who are not at least on a twinset.

Team bailout, much like Mix diving, requires discipline and planing, and practiced skills. You must expect things to go wrong. That is the difference!

Gareth

 

[The Chairman]

I'm shocked (jk not really) that so many people support such an idea.

"Support" is a rather over stating it. I rarely dive in a team and in the rare cases I do, I have never relied on team gas for my bail out. I'm just not into the harshness of calling strategies I don't use "dumb". Dive and let dive. I try to leave political style tactics for politics and keep my Scuba discussions on the friendly side.