Going closed circuit- My journey

[TSandM]

Well, I'm not an RB diver, but as I understand it, the problem is that as you use the CCR for deeper and longer dives, the amount of bailout you have to carry begins to negate some of the advantage of the unit. Some teams have adopted a "team bailout" strategy, where enough bailout for one diver is distributed among the team. I have read several articles where it's seemed quite clear that this is an ongoing controversy among rebreather instructors. So I wondered what a DIR-influenced dive team would choose to do.

 

[nadwidny]

Well, I'm not an RB diver, but as I understand it, the problem is that as you use the CCR for deeper and longer dives, the amount of bailout you have to carry begins to negate some of the advantage of the unit. Some teams have adopted a "team bailout" strategy, where enough bailout for one diver is distributed among the team. I have read several articles where it's seemed quite clear that this is an ongoing controversy among rebreather instructors. So I wondered what a DIR-influenced dive team would choose to do.

Since I don't start my training for a couple of weeks it would somewhat premature for me to say "Well I'm going to do this " or "I'm going to do that". I'm guessing that once we start diving the units and work out stuff like rock bottom for bailout I'll have a better idea.

 

[Gene_Hobbs]

How are your teams going to handle bailout? This has always seemed to me to be one of the biggest questions about transitioning to CCR.

Does this help?

Verdier C and Lee DA. 2008. Motor skills learning and current bailout procedures in recreational rebreather diving. In: Verdier (ed). Nitrox Rebreather Diving. DIRrebreather publishing. RRR ID: 7282

 

[netmage]

Well, I'm not an RB diver, but as I understand it, the problem is that as you use the CCR for deeper and longer dives, the amount of bailout you have to carry begins to negate some of the advantage of the unit. Some teams have adopted a "team bailout" strategy, where enough bailout for one diver is distributed among the team. I have read several articles where it's seemed quite clear that this is an ongoing controversy among rebreather instructors. So I wondered what a DIR-influenced dive team would choose to do.

The recently printed IANTD encyclopedia suggests as a minimum...
Bottom Gas bailout sufficient for 1.5 divers based on worst RMV.
Deco Gas bailout sufficient for 1.2 divers based on worst RMV. (tho I use 1.5)

And for shorter runtimes in the ocean, I think this can work to start, with a few qualifications, and it really comes down to how many failures do you plan and account for, and what options are available to address them.

For example, when we dive locally in the ocean, I prefer a three man team, bailout calculated using 2 people, where the bailout carried by the third is 'gravy'.... In addition, the captain will hang a bottle of 80-100% on the ball, of course this assumes we're not blown off the wreck as well.

In the cave, I much more prefer a 1:1 approach with ample seiging and staging as dive plans permit. The cave is static, there is little extra effort dropping a 40 of O2 at the sign, or if doing multiple days at the same system, leaving an AL80 1000' or 2000' in on egress of dive #1.

-Tim

 

[TSandM]

Interesting article. Thanks, Gene.

 

[rjack321]

You too?? Holy crap. :shocked2:

I only have few dive buddies left that aren't diving CCR. I'm not diving as deep as you so for now, the risks aren't outweighing the benefits for me.

Oi vey. We should burn the heretic now.

I'm not much below 200' so no need for RB technology here. Besides, I have a boat to gaze at lovingly.

 

[Mike Edmonston]

Well, I'm not an RB diver, but as I understand it, the problem is that as you use the CCR for deeper and longer dives, the amount of bailout you have to carry begins to negate some of the advantage of the unit. Some teams have adopted a "team bailout" strategy, where enough bailout for one diver is distributed among the team. I have read several articles where it's seemed quite clear that this is an ongoing controversy among rebreather instructors. So I wondered what a DIR-influenced dive team would choose to do.

Although the bailout gas requirements may be the same (in cf), the placement of that gas is truly dive/expedition dependant. If one is pushing a cave for example, the bailout strategy could be to stage safety cylinders at intervals that allow the team access to gas for a safe exit. If diving in the ocean, bottles can be placed on the downline or carried down by support personnel in case of Emergency. Now if you're diving in 2' vis with a 3 kt current on an exploration dive in open water, you better have enough bailout on you to make it out if you get blown off the wreck etc...

It's all situation dependant... YMMV

Safe Diving,

 

[nadwidny]

Oi vey. We should burn the heretic now.

Well after I did my KISS demo solo, without training, hypoxic mix, no bailout and a couple of other infractions I was told that my DIR halo is not only tarnished but beaten, stomped, dragged through the mud and snapped into little pieces.

I've tried watching all DIR tapes over again, went back and read all of George's posts on the Techdiver archives and I face the direction of High Springs every night but to no avail. I am now one of the damned. Burning would be too good for me. But a whipping, yes, there's the ticket. A nice little whipping, maybe while handcuffed and masked- maybe that's what I need because I've been a bad, bad boy.

 

[JeffG]

I think I'm going to puke.

 

[amascuba]

Well after I did my KISS demo solo, without training, hypoxic mix, no bailout and a couple of other infractions I was told that my DIR halo is not only tarnished but beaten, stomped, dragged through the mud and snapped into little pieces.

I've tried watching all DIR tapes over again, went back and read all of George's posts on the Techdiver archives and I face the direction of High Springs every night but to no avail. I am now one of the damned. Burning would be too good for me. But a whipping, yes, there's the ticket. A nice little whipping, maybe while handcuffed and masked- maybe that's what I need because I've been a bad, bad boy.

Do you have dreams of GI3 chasing you around in a speedo and belly shirt?