Cave recovery - the logistics planning and implementation

[Diving Dubai]

Not wanting to de-rail the EN accident thread I thought I’d open a new discussion.

I’m struggling to comprehend the logistics of a recover operation like this.

What actually happens, and how does it happen

The amount of gas each team member requires, there differ mixes for bailouts, safety stages and deco etc. Do you all have that prepped and ready to go. Similarly their RB units, scooters etc?


Similarly – the victims, had already made one dive placing all their stage and deco cylinders – what happens with the recovery team. Do you take it all as you dive, is their another back up team etc etc. how do you balance detailed dive planning with getting into the cave in a timely manner?

I’m really interested in the logistics and planning behind the operation as well as the steps and different dives you do – in this case (as I understand) Locating and initial evidence gathering, body recovery, equipment recovery. As well as how the Cave rescue knits in with the other emergency services.

I hope those who participate could fell as though they’d but their contribution here – but I don’t want them to feel pressured. I spent 10 years involved in Air crash recovery and investigation so have empathy with those who participated even though the circumstances and aftermath are completely different.

 

[tbone1004]

@kensuf @PfcAJ
tagging these two that were involved in that particular recovery so they see it.

 

[kensuf]

What went into this recent fatality is going to take some time to answer fully so give me some time.

In the meantime, you can look at this article in Advanced Diver Magazine issue #18, which begins on page 28. It discusses some of the logistics that went into the recovery of a double fatality in Eagles Nest back in 2004.

http://www.advanceddivermagazine.com/_PDFORDER/isfg/18aye/ADM Issue 18 master.pdf

 

[PfcAJ]

Logistics were pretty straight forward.

when I got the call I loaded my truck with gases for a deep cave dive and gases for shallow support. In this case I had 15/60 trimix and my rb80 rebreather for the deep stuff and 18/45 and a 32% nitrox stage (open circuit) for shallow stuff. Best to be prepared for whatever task that's needed.

While there was plenty of deco gas in the water placed by the 1st team in, I took my own to drive the rb80 (gotta plug in different gases). I had 2x lp85s plus 1x al80 of bottom gas for bailout, and an 80 of 35/25, an 80 of 50%, and an 80 and a 40 of oxygen for deco/bailout.

My buddy owns a trespresidentes scr which is very similar to an rb80 so no issues with him understanding my unit. I'm somewhat familiar with the sf2 and the configuration he was using so we were good to go in that department for the dive we were doing. I don't love mixing equipment like that but sometimes it's gotta be done to accomplish the mission at hand.

We both rode xk1 scooters and I towed an Xj37.

Our task was to locate missing divers and document as time allowed. I wanted to keep the dive sub 5hrs since it was already a loooonnngggg day before we even hit the water.

Decisions on who was doing what was based mostly on consensus, who had the gear, and who was ready to do what. Imo there wasn't a single person in charge, and I think that's an ok thing. it keeps the field level and gives each team autonomy to make their own choices and decisions.

 

[Diving Dubai]

So the gasses you had ready at home. Is that a conscious decision as part of a "go team" or your normal gear that is re filled post dive.

I guess where I'm going is to try to relate to "normal diving. While I have a ton of tanks filled for my wife and I post dive, we use pretty standard mixes, so the back gas , ponies and deco's can be filled pot dive. But if we're doing something different then the tanks are filled specifically for that dive.

While all my gear is ready, it's not ready enough to be able to pick up and go. Again is this a conscious effort as part of a go team

 

[ScubaDocER]

What went into this recent fatality is going to take some time to answer fully so give me some time.

In the meantime, you can look at this article in Advanced Diver Magazine issue #18, which begins on page 28. It discusses some of the logistics that went into the recovery of a double fatality in Eagles Nest back in 2004.

http://www.advanceddivermagazine.com/_PDFORDER/isfg/18aye/ADM Issue 18 master.pdf

Thank you for the link Ken. That was an extremely thorough report and the graphics helped to visually understand where everyone was located. Although I don't cave dive anymore I try to stay connected to the sport. This was the first time I felt the amount of work and energy that must go into a recovery. I appreciated the read.

 

[kensuf]

So the gasses you had ready at home. Is that a conscious decision as part of a "go team" or your normal gear that is re filled post dive.

I guess where I'm going is to try to relate to "normal diving. While I have a ton of tanks filled for my wife and I post dive, we use pretty standard mixes, so the back gas , ponies and deco's can be filled pot dive. But if we're doing something different then the tanks are filled specifically for that dive.

While all my gear is ready, it's not ready enough to be able to pick up and go. Again is this a conscious effort as part of a go team

First, let me state I am not an IUCRR member and I do not speak for them or anyone else.

The closest dive shop to me that does "tek fills" (oxygen, helium, etc) is 30 minutes from my house, and so for convenience I usually fill cylinders at the tail end of a weekend and keep them full so I'm ready to go for anything that may crop up dive planning wise the following week. At any given time I've got various sets of doubles, stage bottles, and sidemount bottles filled. In my garage right now I have two sets of 104's filled with trimix (21/35 in one set, 14/60 in another), 1 set of 104's filled with 30% nitrox, and 2 sets of 104's with around 2000 psi of 30%. I also have a sidemount set of 108s filled with 10/70 and a set of sidemount 85s filled with 21/35. I have 1 LP72 filled with oxygen, 2x 40s filled with oxygen, 2 or 3 80s filled with 30% nitrox (and 2 or 3 with some amount of 30% in them), 1 80 filled with 50% nitrox, and until a week ago when I taught a normoxic class, I had 2 80s filled with 18/45 (they're nor empty). I also thought I had a 40 filled with 50%, but found out yesterday it only has 1500 psi in it.

I keep these cylinders like this for convenience. Diving the CCR, my sidemount bottles rarely get drained, and when I do a trimix OC dive I either use stage bottles in lieu of bottom mix (saving my backgas for emergencies), or re-fill as soon as convenient after. I usually keep a set of doubles ready to go with 30% nitrox in the event someone wants to do a mid-week dive.

My wife and I were at dinner when we were called about the EN incident. Not knowing anything about what would be involved, when we wrapped up with dinner I went home and prepped deep bailout bottles and deco bottles, packed a scrubber, and was ready for anything. I was also teaching that weekend, and needed to talk with my students before I could head down there (it's not cool for an instructor to just disappear on his students). It was decided by 9PM I'd be part of the Sunday afternoon operation, whatever that would entail, so I also prepared to finish my class (intro to cave) with my students in the morning. By 7AM Sunday the picture was much clearer, and for my role in the operation I only needed a set of doubles with 30% nitrox in them.

 

[tbone1004]

So the gasses you had ready at home. Is that a conscious decision as part of a "go team" or your normal gear that is re filled post dive.

I guess where I'm going is to try to relate to "normal diving. While I have a ton of tanks filled for my wife and I post dive, we use pretty standard mixes, so the back gas , ponies and deco's can be filled pot dive. But if we're doing something different then the tanks are filled specifically for that dive.

While all my gear is ready, it's not ready enough to be able to pick up and go. Again is this a conscious effort as part of a go team

most people I know, myself included, subscribe to some sort of standardized gasses. They may not be exactly the WKPP approved gasses for cave diving, but they are usually close. What that basically means is that for trimix depth, you full with helium, then top off with EAN32. This keeps you essentially diving equivalent O2/N2 ratios as EAN32 which seem to be a close balance between cost/CNS toxicity/narcosis/deco efficiency while not really limiting you. I don't know anyone outside of the hardcore NJ wreck divers that actually dive custom/ideal gas mixes. It's too much of a PITA.

What @kensuf said above is that he basically had mixes for the following
EAN30- good to 120 ish feet depending on your narcosis tolerance. *EAN32 is more typical depending narcosis tolerance*
21/35 trimix-typically used for 100-150ft. Can be pushed to about 170 depending on your narcosis tolerance. 18/45 is another common "light" trimix gas
14/60-good to somewhere in the 300ft ish range. 12/70 is a more typical deep trimix gas for reference.

There really isn't a need for a whole lot more than that. All of this is for decompression diving so where you guys might be choosing EAN36 vs EAN28 if you're diving shallower to increase your NDL's, we would just dive EAN30 or 32 *depending on where in cave country you are*, and deal with a couple extra minutes of decompression for the convenience of having what essentially amounts to 3 different potential gas mixes. Most of the guys like Ken, AJ, etc. and myself included, will have dedicated sets of tanks for different mixes and will try to keep them as standardized as possible. Most mix divers will have the 3 mixes or slight variants of the above in dedicated tanks and some will have a set of air tanks depending on the shops that they get fills. I have a dedicated set of air doubles that I use for teaching so I don't have to worry about lean mixes when I go to cave country. For 60ft in a quarry there is no reason to dive nitrox and they don't bank nitrox in that part of NC so it's easier to have a set of doubles dedicated than to worry about draining tanks to get the right mix.