Stage Dropping

[TSandM]

Peter and I talked about coding regs, but I'm actually more worried about the wrong color reg ending up on the wrong bottle, than I am about the wrong mix ending up in a bottle labelled with a different MOD.

I do not think that this accident could happen, if gas switches are verified by the team. What allowed this to happen was that the deco gas drop isn't a step that's verified, and switches to bottom stages aren't verified. Making an error in the first step set up a problem at the second. To prevent this, you either need to verify the identity of dropped bottles, or verify stage swaps. Although, as I'm writing this, if you have 80s full of deco gas on site, you have the possibility of picking one up in error, which suggests that all stage swaps should be verified. I started to say that I won't do this, because I never have 80's full of deco gas, but I do obtain my gas in Mexico at a place that might. Maybe incorporating an MOD check on the stage into the head-to-toe equipment check would be enough.

 

[rjack321]

Peter and I talked about coding regs, but I'm actually more worried about the wrong color reg ending up on the wrong bottle, than I am about the wrong mix ending up in a bottle labelled with a different MOD.

I do not think that this accident could happen, if gas switches are verified by the team. What allowed this to happen was that the deco gas drop isn't a step that's verified, and switches to bottom stages aren't verified. Making an error in the first step set up a problem at the second. To prevent this, you either need to verify the identity of dropped bottles, or verify stage swaps. Although, as I'm writing this, if you have 80s full of deco gas on site, you have the possibility of picking one up in error, which suggests that all stage swaps should be verified. I started to say that I won't do this, because I never have 80's full of deco gas, but I do obtain my gas in Mexico at a place that might. Maybe incorporating an MOD check on the stage into the head-to-toe equipment check would be enough.

Remember the actual incident happened on an RB80 with a switchblock so its alot harder for buddies to trace hoses with their eyes. It has got to be harder to verify switches on the RB80 which really begs for ppO2 monitoring as a backup. There have been 3 incidents I know of in <3 yrs with mis-understood ppO2s on the RB80.
2x hypoxia (both survived in various states of wholeness)
1x hyperoxia (this death)

I'm never going to be color coding regs or anything else. The damn bottle has 3" high numbers on the side. Those numbers must match the analysis before the cylinder leaves my garage. Those numbers are the only constant which conclusively links the analysis with a safe depth to breath it at.

 

[Cave Diver]

Peter and I talked about coding regs, but I'm actually more worried about the wrong color reg ending up on the wrong bottle, than I am about the wrong mix ending up in a bottle labelled with a different MOD.

I agree. Using identical regs on all my bottles forces me to verify the markings on the bottle, rather than rely on a visual or tactile cue that I'm on the right gas. I'm not saying those of you who choose that method are being complacent and not checking markings, but I can see how it might become easy to do so.

I saw in another thread where Rick brought up the question of a team watching each other, but not really seeing. I'm thinking on our next trip I may bring a mis-marked bottle with me and see if either of my buddies catch it during our s-drills.

 

[down4fun]

I agree. Using identical regs on all my bottles forces me to verify the markings on the bottle, rather than rely on a visual or tactile cue that I'm on the right gas. I'm not saying those of you who choose that method are being complacent and not checking markings, but I can see how it might become easy to do so.

I saw in another thread where Rick brought up the question of a team watching each other, but not really seeing. I'm thinking on our next trip I may bring a mis-marked bottle with me and see if either of my buddies catch it during our s-drills.

It's not stage dropping, but in ccr we almost always carry multiple bailouts and are at risk for the same type of errors.

i Agree that identifying the reg isn't enough.

A buddy of mine accidently swapped regs on his bailout bottles thus causing him to place the bottles on opposite sides as he was relying on identification of the regs for placement not the MOD stickers.If he had to bailout he could have been in trouble. He now requires a buddy to verify his bottle placement and MOD.

I watched another buddy put there rich mix on the lean side on the boat and pointed it out. When dealing with multiple bottles stuff happens and we have to be careful and though ultimate responsibility lies with ourselves it doesn't hurt to police each other too.

 

[CyprusSeb]

Labels wouldn't work very well in a silt-out ... which is something that cavers need to plan for (at least Florida cavers) ... creating some unique way to identify the gas by feel would be more effective ...

I don't disagree...and of course all these things vary depending on what style diving one does. However how often is someone generally switching gasses/bottles silted out? I understand it happens...but even if it happens 20% of the time, that still leave 80% where labels can help.

 

[rjack321]

I don't disagree...and of course all these things vary depending on what style diving one does. However how often is someone generally switching gasses/bottles silted out? I understand it happens...but even if it happens 20% of the time, that still leave 80% where labels can help.

Don't label your regs. You'll put the wrong one on a bottle or have to switch them around someday and your whole "system" will fall apart. Label the bottle with MOD in big letters. Analysis tape must match the MOD before diving (or in my case before it even leaves the garage). Bottle MOD must match the depth on your gauge or you don't switch. Buddy confirms depth against MOD as a 2nd layer. That's it, 1 strategy all the time. No special zip ties and/or color coding business.

 

[ScubaFeenD]

From what I have read it wasnt a failure of the protocol itself, but instead a failure to adhere to the protocol. So, the procedure wasnt wrong, and making it more stringent, or color coding it, or whatever wouldnt have made this incident not happen. It was human complacency, which is really unfortunate. Now, if the procedure had been followed perfectly then I would say additional levels of checks might be needed....might. Anyway, the comments about checks on bottle drops are interesting, and once I move to that level I will certainly keep this incident in mind.

 

[CyprusSeb]

A buddy of mine accidently swapped regs on his bailout bottles thus causing him to place the bottles on opposite sides as he was relying on identification of the regs for placement not the MOD stickers.If he had to bailout he could have been in trouble. He now requires a buddy to verify his bottle placement and MOD.

This is no different than someone labeling the tanks incorrectly, forgetting to charge batteries, not making sure you have everything. When you fail to do something correctly in pre-dive, expect to fail during the dive. The only reg I have different is my 100% bottle...mainly because it's less forgiving. It's also a 7L tank. 50% also a 7L tank and always gets the same reg set (with the quickshot inflator as mentioned above). Travel gasses at that point get identical regs and get zipties on the hose for identification purposes if picking them up in a silt or black out. Depending on the dive I'll sometimes attach a spare light to a tank I'm dropping (mind you this is inside wrecks, not caves)

If I screw up my reg setup pre-dive then it's my fault, nobody elses. If I don't label my tanks and according regs (I remove the tape after dives so I'm forced to check and label) then it's my fault. Your buddy/team is there to help you not babysit you. Only person looking after me is me.

 

[jjones9527]

Don't label your regs. You'll put the wrong one on a bottle or have to switch them around someday and your whole "system" will fall apart. Label the bottle with MOD in big letters. Analysis tape must match the MOD before diving (or in my case before it even leaves the garage). Bottle MOD must match the depth on your gauge or you don't switch. Buddy confirms depth against MOD as a 2nd layer. That's it, 1 strategy all the time. No special zip ties and/or color coding business.

Exactly. We do multi stage, multi gas dives all the time, and every switch gets verified. I'm kind of shocked that this isn't SOP in caves as well.

 

[CyprusSeb]

Don't label your regs. You'll put the wrong one on a bottle or have to switch them around someday and your whole "system" will fall apart. Label the bottle with MOD in big letters. Analysis tape must match the MOD before diving (or in my case before it even leaves the garage). Bottle MOD must match the depth on your gauge or you don't switch. Buddy confirms depth against MOD as a 2nd layer. That's it, 1 strategy all the time. No special zip ties and/or color coding business.

The failure of any system is just that....a failure. My regs are labeled as I'm labeling my tanks...every morning...same thing. If something goes wrong with my reg set for example and a different set of regs have to go on there....I put a new piece of tape on the new regs and write MOD on it. It's that simple. It's part of my pre-dive routine. After I'm done diving the tape comes off. Me labeling my regs is just an additional step which takes a whole 10 seconds after I label my tank. That's it, it works and makes things less complicated when I have 6 second stages around me. If it's not for you then it's not for you.
I drop two tanks once....get back to the tanks, area is silted out and there are now 6 tanks there. Zip ties let me identify the tanks a whole lot quicker than feeling first and second stages. One zip tie on the hose and one on the bottom bolt snap..."yep...thems mine"