Accident Analysis of Guangxi China Cave Divers Accident (according to DIR philosophy)

[PfcAJ]

AJ,
Thanks for the analysis, it's very informative. Sorry for the late reply, been diving.

I totally agree with what you said, that having to solve problems while you know your gas is running out is scary. My skin was crawling as I was reading that part of the account.

A couple of questions:

- You mentioned using rule of "thirds" is not suitable for a dive like this. What kind of gas plan does GUE use for a case like this? How much gas needs to be carried, and how much placed in reserve safety bottles along the line?

- When you say they should not use "backgas" do you mean they should be using rebreather on this dive?

Thanks.

I don't think you'll find any sort of an 'official' recommendation. These types of things are grownup dives where the divers need to make their own decisions. I can only relay what I know about longer/deeper dives and how successful teams do them, but even then, its not 500ft+. Its longer range cave stuff in the 200-300ft range.

I think of gas more as 'time' vs some sort of "1/3, 1/4, 1/6" or whatever gas rule that might not really provide enough contingency gas. Conversely, you might end up bogging yourself down with a dive shop's worth of scuba tanks and go no where. Calculated balance.

Not touching backgas means that ALL the gas in the doubles is reserved. The dive is done on stages only. The same holds true with the RB80 on cave dives; the backgas tanks are bailout. When backgas alone isn't enough to get you completely out of the cave, safeties are needed. They might be needed sooner than that, it all depends on the situation.

I'll compare 2 caves that Litehedded and I have been exploring for a few years (slowly, though, due to conditions). In the 1st cave, the safety depot is at 1000ft in at a depth of ~110ft. In the 2nd cave, the depot is at ~1200ft in, but 205ft deep. The 1st cave is WAY more challenging despite the significantly shallower depth. There's a lot of variables that go into setting up a cave for exploration.

There's no 'class' for that stuff. You a) work with successful teams and learn their methods and b) build up a significant amount of experience and apply it to the situation. There is no 'rule' that universally applies.

Go slow, link up with divers doing the type of diving you aspire to do, dive with them, learn from them, and go slow.

Did I mention to go slow?