Calculating Search gas

[jeandiver]

OK , I have one for all to think about...
We know what the rules say on a Lost Buddy...Search till you hit 3rds. (I was taught to recalc from the point we found we had a lost buddy).

So , that's the rule.

BUT...from a human point of view , how MANY of us in the moment would "BLOW" 3rds to keep searching a little longer. Of course , I know you don't want TWO recoveries.

I mean I know the rule.
But ...

You all see what I mean?

OK , go ahead and blast away at me.

I know if I express my opinion , people are going to jump all over me , but I KNOW my personallity and , well ...

This is just speculation on my part but knowing Bruce as I did , well , if HE WAS searching for a missing buddy , it would NOT shock me one bit. As a previous poster said , he was a Marine , and well...

Jean

 

[bsee65]

I would need a plan to exceed my limits. If I thought my buddy was stuck in a spot like Harry's, I would try to go through and find him, knowing where the end is and believing that I could get through and still make it out with gas. On the other hand, I might not travel open-ended in a direction that would leave me trapped and unable to exit without some evidence that I was likely to find my buddy there. The higher the likelihood that my buddy was in the area I planned to search and in trouble, the higher the likelihood that I would stretch the limits.

Without knowing in detail what the plan was and what signals were passed between the buddies, it's hard to know what they were expecting of each other. Even getting the answers from Bruce's diving partners, we still couldn't know for sure what he was thinking.

One question about the gear and the dive site. Would Bruce have had a computer, and does the dive site force enough changes in depth through the cave system that a download might provide an ability to trace his path?

 

[jviehe]

I would hope buddies discuss this before hand. I would personally prefer that my buddy save themselves if I got lost, after a short search. Once you lose a buddy, your ability to recover from some problem of your own goes down. Therefore the longer you spend under water without a buddy, on a dive plan that includes a buddy, increases your risk of incident.

If anything this should teach you to be even more aware of your buddy. Cave diving of course has the caveat of purposefully putting yourself in a situation where you may get visually seperated, such as entering a cave in zero viz. Or passing a restriction. Just the risk you have to accept. As I said, in a case where we were unreasonably seperated, and a short search fails to locate, I would hope my buddy saved himself, and would want me to do the same.

 

[DA Aquamaster]

OK , I have one for all to think about...
We know what the rules say on a Lost Buddy...Search till you hit 3rds. (I was taught to recalc from the point we found we had a lost buddy).

So , that's the rule.

BUT...from a human point of view , how MANY of us in the moment would "BLOW" 3rds to keep searching a little longer. Of course , I know you don't want TWO recoveries.

I mean I know the rule.
But ...

You all see what I mean?

I agree Jean. Not using the reserve third is not a consideration, as it is for an emergency and that is exactly what you have at the time, so use a suitable protion of the emergency gas. Consequently, I would push into my reserve as much as was prudent to extend the search but I would also be figuring the probabilties of actually having enough gas left to help a buddy in the event I actually found them.

That would involve assuming they had similar gas reserves to mine if they are someone who'd stay calm when lost off the line, or alternatively assuming they have significantly, less gas than I have if they are prone to get excited if lost off the line. Consequently, I'd stay longer searching for the former than the latter as I could get the calm buddy out on less of my gas than the not so calm buddy.

Staying too long searching, using all the reserve and in the process cutting my gas razor thin with just enough to get me out if no delay occurs puts me at risk. This is especially true if I then encounter the buddy on the way out and it does the buddy no good as I have no way to help. At that point, the best case is that you just give them false hope before you leave them (which will leave you with some serious emotional scars), and the worst case is a double fatality if you did not have what it took to leave them at that point.

To make the gas plan work better, if the buddy is not in the immediate area and there is no clear evidence where they may be (no search area more likely than another) I would search farther into the cave first, then retreat and search the areas closer to the exit on the way out as the available reserve potentially increases closer to the exit, extending the time you can search.

Also, if I searched a side tunnel using a reel or spool, I'd leave it in place when I reverse and return to the main line as it creates more line for the lost diver to potentially stumble upon, and I can move quicker to a new search area if I am not reeling in line. We can clean it up on a subsequent dive.

 

[Juno]

The amount of gas you would use or leave with should be something you agree on with your buddy. Ask them how fine they would want you to cut it and how fine they would cut it.
You might be surprised. Your buddy may not want you to risk your life within an inch of itself for them.
If I screwed up and got us separated, yes I would want my buddy to search for me within reason but in no way would I want them to kill themselves over it. I want them safely out of the cave.
Some worst case scenarios.
Buddy 1 get's seperated and dies, buddy 2 dies looking for him.
Buddy 1 gets seperated and lives, buddy 2 dies looking for him.
Or Buddy 1 or 2 is on shore with 2000 psi in their tanks explaining to the family why they didn't look a little longer.

 

[Rick Murchison]

The instant the decision is to go into search mode, my gas requirement calculations change, based on "what does it normally take me to get out from here?"
I then set my abort gas at somewhere between four and eight times that amount, depending on conditions.
For example, if I need 200 psi to make my normal exit, then I'm going to double that so that if I find my buddy as he's running out of gas I have enough for both of us - then I'm doubling that again for the excitement factor - that's four times. If the visibility is blown then I'm doubling it again, eight times.
Note that this is not an exit gas supply point, but rather an abort point for a position - that is, the point at which I begin my retreat towards the exit... I can retreat at one fourth to one eighth my normal speed and still retain my abort gas for my position as that position gets closer to the exit.
Rick

 

[Cave Diver]

Among the considerations have to be how heavily trafficked the area is. The greater the possibility of making it to a point where you might encounter other dive teams that may be able to lend assistance, either entering or exiting the system, would factor into the decision. If you're in a remote area or in a lessor travelled system, the conservation of gas becomes more critical.

 

[Rick Murchison]

Among the considerations have to be how heavily trafficked the area is. The greater the possibility of making it to a point where you might encounter other dive teams that may be able to lend assistance, either entering or exiting the system, would factor into the decision. If you're in a remote area or in a lessor travelled system, the conservation of gas becomes more critical.

Meeting another team immediately changes the equation... in general, (obviously specifics of the situation may dictate variances from the general protocol) the person with the least gas should exit for help/more gas, and the rest should search. Meeting another team vastly increases the chances for a successful outcome.
Rick

 

[UCFKnightDiver]

I think my turn pressure would depend on many factors most if not all previously stated by others; What kind of flow is this cave, high or low, high traffic or low traffic etc.? Also when I reached the point where I must turn and stop searching I would clip wetnotes to the line saying that I have left the cave, and a backup light.

 

[diverdoug1]

I would hope buddies discuss this before hand. I would personally prefer that my buddy save themselves if I got lost, after a short search. Once you lose a buddy, your ability to recover from some problem of your own goes down. Therefore the longer you spend under water without a buddy, on a dive plan that includes a buddy, increases your risk of incident.

If anything this should teach you to be even more aware of your buddy. Cave diving of course has the caveat of purposefully putting yourself in a situation where you may get visually seperated, such as entering a cave in zero viz. Or passing a restriction. Just the risk you have to accept. As I said, in a case where we were unreasonably seperated, and a short search fails to locate, I would hope my buddy saved himself, and would want me to do the same