Incident on 80m (avg) - 30 min BT dive

[fsardone]

I have been lurking for a while ...
I am advanced (hipoxic) trimix and an aviator, who knows how to fly manually but uses automation to reduce the workload. When in CCR I prefer to shoot an DSMB to stabilise me at any depth less than 20mt, especially on long 6mt stops.
In term fd experience I had to rescue a guy who had a timpanic perforation (infection not failure to equalise) at 60 meters and he was unable to tell up from down. Luckily no vomiting but spent quite a long time hanging on the shot line. Me working his deco and controlling his ascent. At best this is very stressful for the rescuer, which needs to have high self confidence to handle his task load and the additional one.
So well done (to OP and his team not me ...)!
My takeaway here (and in my incident) is we should be able to cope not only with our issues but with those we are diving with.
GUE standardisation should let you dive with strangers, but as nice as it might ght be (other have pointed this out before me) understanding the other person before going for a big dive is important.
In my work the minimum fighting element is the pair: two jets of same nationality/wing/squadron, fighting in a bigger package. Those two know each other, have been doing flying training together and have proven their ability to each other. Standardisation comes into play integrating the pair into the rest of the package. I feel the same into diving.
Face to face briefing is a must in flying should be in diving where standard procedure are quickly refreshed so we know what we are going to do.

In diving as in flying a good one is one you can talk about ... not lying in an hospital bed or wheelchair. Just my 2 cents and thank you for sharing good learning here. Thanks to the mods in keeping the thread clean.

 

[_Ralph]

Glad to hear of the good (while puckering) outcome!


One thing to comment about the recent comments about vetting and questions before a dive

One of the things I love about GUE, is that little of that is required ... A quick chat to find out T1? T2? go through the predive and do the dive. I've dove with lots of divers around the world with very little 'chatter' before the dive (many I meet as we load the boat) due to the standards and procedures.

RMV/SAC doesn't come up, as the gas planning is already heavy on the conservative side (especially as you progress, sometimes maybe not conservative enough at the Fundies or specifically, new diver level)

The only thing I do verify, is that we are all on the same page. Are we doing a T1/DPV/Rec/Wreck/Photo/Fishing/Combination off all the above dive? Cool, any questions? Let's go!

_R

 

[beester]

The problem with this is that you sometimes see stress only afterwards, you missed the signs/signals when it happened. That is really difficult.

I know how difficult it can be to ask the right questions before a dive and be aware of signals someone is not comfortable. Some divers look experienced if you talk with them but are not. Or really lie.
The ones who tell you 'I am not so experienced at this depth' are not the ones you have to worry about. They know their weaknesses, or are at least not ignoring them. You only have to think by yourself or by your team, can we handle an more inexperienced diver on this dive? The 'if you don't feel confident to do the dive solo, then don't do it' is right in this. It is not telling you you have to dive solo, it is a DIR approach that you too, that every teammember must feel good enough to do the dive AND be able to help a teammember. If not, then you have to talk about it. Every experienced diver was an inexperienced diver, so give everybody a chance. But do it within your abilities.
I guess the ccr divers where most experienced. Did they react on "mistakes" of diver X? Or let they do it the other oc divers? This is importent for YOU for learning from this. You wrote you are not the most experienced diver on this level. Not wrong, but then ask by yourself: did you feel confident enough to do 30 minutes at 80m self sufficient in a team or in this team? Or better: Did you feel confident enough to do this dive with a team of less experienced divers than you are (ok, maybe you didn't know the team experience, but you can ask this yourself now)? If not, not wrong, but maybe you reacted a little bit stressed too on the first signs (soloswitch, holding a line, etc). If someone does a soloswitch and I see it is the right cylinder, I will not make a problem under water, think we will discuss this afterwards. If someone says cramp and grap a line, ok, everything is safe, just ask about it after the dive. A slow bottlerotation. Just relax and maybe help. Talk about it after the dive. Maybe just not focussed enough today because of workstress. Not holding bouyancy. PLEASE let a diver grap a line. You sign it to the diver that he looses bouyance, maybe grap him to get the right depth again, but if there is an option as a line or smb, USE THIS. NO STRESS. Stressing under water by you or another teammember can make MORE stress by diver X. Holding a line means at that moment it is in control ( I agree a diver at this level do not need a line, but). That is most important. See the dive this way..

Quite a lot of stuff here Germie. I'll try to answer and hopefully I don't miss out on anything.

First of all I have contacted the JJ diver that I know very well via messenger to see if he has further info or can get diver X to speak up. No reaction yet. We'll see and it might shed some light.

To your questions / remarks:

- Identifying if someone is stressed: I believe I know most of the signals that could identify someone being stressed. Diver X wasn't overly quiet or very loud, he wasn't fiddeling with his gear, he didn't look like he felt out of place, I watched him as well during the boat ride out and during setup all was well. The equipment check before the dive went well. No clear indicators. Obviously there was the language barrier but when it comes to id-ing stressors language is in any case not the only way to check.

- My experience: I felt confident doing the dive. I would have felt confident doing the dive just with diver X as well, but I would have asked more questions in this case for sure. It wasn't my first 80m-2 hour deco dive and I've been slowly increasing the range since I did T2 in beginning of 2016. By the way I don't know if diver X is less experienced. I'm assuming.

- Solo switch: We didn't over communicate. I understand that over communication is as much a stressor as is too little communication. It needs to be the right communication and in this case except for me taking out my wetnotes and starting penciling down "WHY DID YOU SWITCH SOLO?" and starting a written discussion at 60m during ascend phase, there was no way to clearly communicate our worries. Me and my RB80 friend just eyed each other, did the "look at him / keep watching him" signal to eachother and we double checked his switch gas to make sure he was on the correct one.

- Tank rotation (9m) I noticed him sinking and signalled my RB80 buddy to stay at 9m I followed him down and I kept in close contact to him, when I saw him struggling I tried to make him aware that he was sinking away, but he was taskloaded so at 13m I made touch contact, he realised he was sinking and we stopped sinking at 15m. I helped him with the tank rotation and we moved back up... then we went to O², and he went into cramp. At which point he went to the rope. I tried to uncramp him and after it stopped he wanted to go away from the rope but we told him... keep holding the rope, which he did.

Totally right that you as a team have to be aware that you can also induce stress instead of taking it away. On the other hand it is a thin rope to walk on between inducing stress and not helping enough.

Cheers B

 

[beester]

Then back to some things before the dive:
Another important thing to know in mixed teams: did the JJ divers had teambailout or bailout for their own? This means on a ccr you need at least 3 cylinders if you do bailout for your own. In teambailout for the ccr divers this means they are NOT carrying cylinders for the OC divers. Doing 2 hours deco will mean for some oc divers that one ali 80 with 50% and 1 with 100% is not enough to hold 1/3 reserve. Is talked about this? Was it really 1 team or was it more 2 teams?

Is talked about who is the deco captain? Who switches first, second, third is less important, but someone must be more or less the 'boss'. Normally this is one of the most experienced divers, but there can be a reason to let this do by a less experienced diver to gain experience. From what I read here, a diveplan is made, everybody agreed, but if you don't know the experience from every diver, some more details can be needed. If you are not so experienced this can help you to relax. Or diver X. And this was not discussed?

Yes, I have taken less experienced divers on more demanding dives. But I told other teammembers then: I will be responsible for him. We play the game, but if something goes wrong I will be with him. Then not 3 divers reacting, which can give more stress.

And remember: nobody is perfect, everybody can get into panic or make mistakes. I will be only angry after such a dive if diver X would ignore his mistakes. (yes such divers are there too). Most will give you a reason if you talk to them. And then you can learn and diver X (and the rest of the team).

First part of this goes back to us not identifying a diver not being on the same page. I'm having a long and hard look at how to handle this in the future. How to make sure that although we are all GUE divers, we are still on the same page. However when it comes to the procedures you describe, this should have been very clear. All things that are not standard operating procedure were discussed. (the fact that diver X didn't know all the SOPs is of course part of the issue we had. ) Gas plan is standard operating procedure. We do calculate reserves in our deco gas to solve lost deco scenarios.

For example the JJ divers were carrying their own bail out with the same standard gasses as us. This was clearly communicated. Also clearly planned was that they would dive as a 2 buddy team and we (me and diver X OC and RB80 friend) as another team. We would stay together with 5 but for example if one of the JJ divers had an issue during decent and had to bailout they would bailout with 2 not us 5 together. In the end the JJ divers did the same dive and we started our ascend at the same runtime, they did differ a bit in deco profile because they had a shallower average depth (on most depths until 9m stop they were 1-2 stops above us (3-6m)).

When X ran out of O² (he was also almost empty on 50%), I could have shared my O² and we could have started a "lost deco gas scenario" but this would have maybe caused more stress because it involves more switching, me being very close to him, etc. In this case I think it was the correct decision to signal the JJ divers and ask them for their unused O² bailout.

There was no additional staged gas (on a trapese or whatnot) as additional reserve. With a team of 3 (or 5 if you count the JJ divers) it wasn't felt necessary.

In our team of 3 I was the deco capitain. Although it wasn't much additional workload because we didn't have to recalculate, as we were on the ball on bottom time and average depth.

I believe that we handled the sandwiching the stressed diver quite well. It wasn't us 2 hanging so close as to not give him breathing room, but really both me and RB80 communicating on who does what. For example we clearly signalled that I would follow and help X out with the tank rotation and RB80 would stay at 9m and reference the line to make sure we didn't drift off and lost visual to the line.

O² (only 50b) was communicated by RB80 to JJ divers and he assisted in helping out (before loss of buyancy of X) with handing over O².

I stayed close to X after he redescended and he was on the line, while RB80 stayed a bit back but still in line of (my) sight.

Key remark (as I already stated):
- I believed X was an experienced GUE T2 diver. This believe was erroneous.
- X didn't speak English (just a few words), French, German, Dutch... so communcation in any case would have been difficult (would have to play it via the JJ divers who we know well and are his fellow country men).
- Because of assumption above I didn't ask the right questions. Because many to talk about topics are implied by the T2 qualification and known. For example, we don't need to discuss lost deco gas scenarios because everybody (on T1/T2) level knows these and in gas planning sufficient reserve is already planned in without having to mention it separately.
- X was put in our team because from pratical point of view it makes sense to team up the OC divers, RB80 buddy stayed with me because we are a team and because he needs to make gas switches just the same as us poor OC divers.
- I don't blame X for anything. He stayed reasonably calm through this whole ordeal, and didn't submit to panick. The only thing that I can "blame" him on but it's a shared blame is not to speak up if he felt out of his "depth". But I understand totally why this can happen (peer pressure, language barrier). Next I'm not really sure if he was out of his depth or just had a bad day. We are all human.

Cheers
B

PS: split in 2 parts because the board couldn't handle more than 10000 characters posted :-D

 

[beester]

In my work the minimum fighting element is the pair: two jets of same nationality/wing/squadron, fighting in a bigger package. Those two know each other, have been doing flying training together and have proven their ability to each other. Standardisation comes into play integrating the pair into the rest of the package. I feel the same into diving.
Face to face briefing is a must in flying should be in diving where standard procedure are quickly refreshed so we know what we are going to do.

In diving as in flying a good one is one you can talk about ... not lying in an hospital bed or wheelchair. Just my 2 cents and thank you for sharing good learning here. Thanks to the mods in keeping the thread clean.

Thanks for your post Fsardone. Much appreciated. I think part of the issue for me was that I was diving with my "wing man" (or rather it was the other way around, he was element/flight leader, I was wingman, him being more experienced). The issue (too little communication) maybe resulted also a bit from this fact. I was totally in my element because I was diving with my "element leader/flight leader" who I know very well and have done big dives with. We are very much attuned to eachother, having the same SAC, same way of communication, a lot of trust between us, etc.

So while (even within GUE T2) I would have asked maybe a bit more questions to X had I dived just with him (just to get a feel of the guy, not really dive related), I didn't because I was primarily diving with my "element" (RB80 guy).

 

[Germie]

Here I think the language, not speaking dutch, german, english or whatever made the communication more difficult.
I dive and have dived with all different kind of divers, trained by all different agencies. It starts with communication. Don't forget that 80+ is a depth that is not done in every full trimix/T2 course (I believe in T2 the max depth is 'only' 75). This can give extra stress. It is REALLY deep.

SAC/RMV not important on this level? It is. Being does not mean you can stay 30 minutes at 80+m. I had a student who could do a reasonable dive at 55m, so certifying at normoxic level was possible, but he was not able to get his sac/rmv down. So at 80m, he would have to take a twin15 or 18 to do a normal bottomtime. But how will you handle the decogases? I have told this. I don't know if he really wants to go on the full trimix level, but even if you are capable for doing the dives as have enough skills/bouyancy/no stress/etc, if your sac/rmv is too high, that can be limiting too.
For me if I am a paying customer on a fundive, I don't mind the background of a diver, agency is not important, carrying cylinders left-right not important, doing rotations or not, not important, best mix or standardgases not important and we can discuss (all these things have nothing to do with a non skilled diver, there are really good bestmix left-right no rotation divers), but I want to know if I can do a reasonable bottomtime. So the question will be done about sac/rmv. And of course I want to know if there is extra gas on the boat or there are safetydivers.
Beester, as you wrote he used a lot of ean50 and 100%, I am really curious how much backgas was left. I have seen divers lying about their sac/rmv too. REALLY this happens. Lying about it during the dive about the pressure left in cylinders as they didn't want to be the one who could not do the maximum planned bottomtime. If you see a diver has left not a lot of decogases at the end of the dive, I would ask friendly about his backgas too.

At the end, I have made a lot of nice dives on different places of the world, technical dives too, with unknown divers. Met really nice people, have been invited to other divesites, etc. So I am always open to dive with new unknown divers on nice spots. You was open here too, this was in your eyes not the best dive. But give such a diver a second chance if it sounds all reasonable. And give a new unknown diver in the future a chance too. You will become more experienced and maybe it will bring you and/or your team to new divesites somewhere in the world.

 

[Tassi Devil Diver]

I need to ask what is the point of tank rotation seems it was something that added to the incident. Tank rotation is not something I have come across given I and many of the people I dive with use the rich right lean left method, seems a lot less fafing around for a gas change. Even if you do insist on leashing off the oxygen why not bring down to the right side for the gas change.

 

[PfcAJ]

I need to ask what is the point of tank rotation seems it was something that added to the incident. Tank rotation is not something I have come across given I and many of the people I dive with use the rich right lean left method, seems a lot less fafing around for a gas change. Even if you do insist on leashing off the oxygen why not bring down to the right side for the gas change.

All bottles are worn on the left. Tanks on the right interfere with the long hose.

Lean left rich right can also easily lead to gas switch mistakes if the wrong tank is in the wrong place. Tank position is a weak indicator of oxygen content.

 

[cavedivingwoman]

'Following this with interest. Beester, it sounds to me as if you and your fellow divers did a smooth job of containing an unanticipated situation. What is the GUE culture about discussing the issues you raised (especially vetting other divers)?
best,
Barbara

 

[Germie]

Not part of the discussion, but I see here questions about why rotations and why left-right method. Just some things to think about:
Both ways, left-lean-right-rich or bottle rotation work. Both have disadvantages and advantages.
In most agencies you can choose your own way. I always learn people the rotation. But if they want to do it left-right, they can. BUT I try to find a way to get the longhose stucked under a cylinder. If they can handle it, I will not say no.
But for myself I prefer the allways left way with rotation and on a leash. And I prefer the leanest gas on the outside left. So the richest is under.

Making mistakes by taking wrong cylinder can be done with only stages left with oxygen on leash and left-right method. If you carry 2 cylinders left, do you carry the richest gas upper or under the other cylinder? And why? Just to think about.

First you can still make a mistake by putting the both cylinders in wrong position on the left side. If you have normally the richest gas outside, you can make a mistake by putting it inside. So that is NOT different from the left-right method. Taking a wrong cylinder can still be done. So there is no method that is better than the other.

If you have the oxygen on the outside or the richest gas, and the leaner gas under, there is a risk that in a stresssituation you take the richest gas. That is a risk. The outside cylinder is the easiest to grab. This is important if you dive ccr. In a real emergency there is not time to do complete checks. A CO2 hit means asap go to a breathable gas.

Carrying the richest cylinder on the outside means most streamlined as you normally first empty the under cylinder. But cylinders on a leash standing right up on your butt is not so nice for some cave environments (if you have to take them and not drop them).

Using the left-right method means the longhose can be in the way. So that is a real disadvantage. When doing this diving ccr you don't have this problem anymore (normal non DIR CCR config, no longhose needed).

Doing rotations in strong currents where you absolute have to hold a line can be more complicated. Or in extreme cold water when your hands get cold. A tank rotation is not difficult, but it needs some concentration and good bouyancy.

If you have only 2 cylinders on the left side (and one or more on the leash), if you switch from one direct to the other there is no option to grab the wrong one. If you go back to backgas and stow the used gas and then go to the next gas there is a chance you grab the wrong one.

And believe me, every theoretically wrong grab of gas has happened somewhere on a dive. Maybe not in your team or you cannot imagine it can be done, but it is.

So every method has good points and weaker points. I prefer the 'DIR' method when diving OC backmount. But will not refuse someone who uses left-right. Just check extra if the longhose is free. Checking cylinders must be done allways.