Camerone
Contributor
As a trained CCR Cave diver (IANTD) I have to disagree. You're diving by a _different_ set of thirds than an OC diver. You have four limiting factors for your loop: Oxygen (which is based on metabolic rate...effectively a constant drain), diluent (not thirds-based, but profile based on the cave), scrubber duration (pure rule of thirds - a three hour scrubber is one hour in, one hour out, and one hour to sort s*** out), and bailout (distance driven, just like regular OC air consumption).On CCR you're not diving by rule of thirds.
So there is rule of thirds in there, it's just applied differently.
Bailout strategies are possible in several ways. There's the normal "rule of thirds" strategy, which requires a LOT of gas, but is safest. You take your own bailout, and you make sure it follows the rule. There's the "just enough" where you figure your bailout, and you make sure there's just enough to get you to the surface, and you rely on everyone on the team carrying "just enough" for the weakest guy, and then there's full-blown team bailout, where you figure out rule of thirds for the weakest guy and then split up the gas carrying by team so everyone takes a portion.
I prefer the "just enough" strategy. Reasonable gas carry loads, and a fairly good margin for safety.
Note that as a CCR cave diver, you can safely do things that you cannot do on O/C. Most of the time, the limiting factors for a CCR cave dive are either scrubber duration or bailout penetration distance.
If bailout is the limiting factor, when you hit your max pen distance, you can always come back and explore side tunnels until you hit scrubber thirds or another limiting factor. Coming out and going in somewhere else is perfectly fine, as long as you never exceed the distance you can swim out. On O/C, when you hit thirds, you start to exit, and you don't go meandering down side tunnels for kicks.
There's a lot of nuances to CCR cave diving, but I'm a huge fan of having the extra time and flexibility that the unit allows in the overhead environment. You just have to understand what you're doing with it and how the tool has to be applied...