a hypothetical for discussion

ok - you and your familiar, similarly experienced full-cave buddy with similar sac rate plan a circuit. you are at a system very much like peacock (and with the same names and same relative distances) but either it is deeper or the distances between openings are longer or your sac is not as good as it is.

you set up one side by going up the peanut tunnel & putting in a jump at crossover in your usual manner. you go up crossover to somewhere in the middle, hit thirds, drop your cookie(s), and turn the dive. you exit without incident and have a surface interval.

you both now go up the pothole/olsen line and put in the jump to crossover. just as you get to your cookie (which might be a hair past thirds in a theoretical way that can't be measured, but is at thirds by the tolerance of your spg), there's some disasterous happening & one of you loses your gas.

you quickly & smoothly start air-sharing, right at 2/3 gas. viz is intact, the line is fine.

do you:

1) keep going to complete your circuit. it is verified line, and shallower than turning around, but will be at the ragged edge of your gas.

2) turn around and go back out the way you came. it is also verified line, but a bit deeper, and might be past your available gas. you could possibly go out pothole. that line is unverified.

3) turn around and head for olsen. you would go back over your jump then turn left instead of right. you have been to olsen before, but not on this trip/not for several months. it is a closer exit by far, but the line is unverified by you recently.

what would you do? assume a small amount of time/gas lost for discussion, but not more than a couple of minutes.

would it matter if as your team was getting in, another was getting out talking about a nice dive to olsen? or not?

would it matter if you had each put a tank of o2 for deco in the cavern?

aaand...go!

Id definetely head for the pothole jump and evaluate from there weather to surface in Olsen or continue toward pothole depending on remaining gas and stress levels.

I would turn and attempt exit at Olsen......if exit from Olsen wasn't possible, then Pothole would be my second choice. I would want to get to the nearest exit as cleanly and quickly as possible. End of story !!!

None of the above. I don't push my gas management that much. The most I'll push anything is 1/3s + 100. So if I start with 3600, my turn pressure is 2500 leaving me 1100 for exit and 1400 for emergencies. I do this in systems like JB or Devil's. In a system like Peacock, Twin, Hole in the Wall, I dive 1/3s + 200...3600 starting, 2600 turn, 1000 for exit, 1600 for emergencies. If it's a new system or involves advanced stuff, like really tight sidemount passage, I dive 1/4s. This is also what I teach my students because of the possibility of something like what you describe in your scenario. If you need more gas to do the dive, then get larger cylinders or bring a stage.

Given your hypothetical I would head for Olsen. If we were unable to surface at Olsen, next would be Pot Hole. If Pot Hole didn't work out I would head for my deco bottle, but usually that is around 30 feet so it is pretty close to the surface. Getting on O2 means the luxury of a safety stop, but if I was still on back gas the safety stop would likely not happen since we would probably be SOL by that time.

All of the diving would be near the ceiling to take whatever advantages there are from being even a few feet shallower with regards to Boyle's Law.

Your hypothetical is pretty specific, so I'll keep my answer limited to your scenario.

Mark Vlahos

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Originally Posted by BabyDuck

1) keep going to complete your circuit. it is verified line, and shallower than turning around, but will be at the ragged edge of your gas.

2) turn around and go back out the way you came. it is also verified line, but a bit deeper, and might be past your available gas. you could possibly go out pothole. that line is unverified.

3) turn around and head for olsen. you would go back over your jump then turn left instead of right. you have been to olsen before, but not on this trip/not for several months. it is a closer exit by far, but the line is unverified by you recently.

would it matter if as your team was getting in, another was getting out talking about a nice dive to olsen? or not?

would it matter if you had each put a tank of o2 for deco in the cavern?

aaand...go!

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I don't agree with, or understand the "might be past your available gas" comment.... 3rds is 3rds is 3rds...

I havn't been to Olsen lately - last time I recalled - I thought the sink was visible from the Crossover jump... so from that perspective - I would consider it verified and egress there. Knowledge of the cave comes to bear here. I may have to look tomorrow - on the map it looks further...

I'm also w/ Rob - when calc'ing gas we round down, so there is always a little gravy.

On points #1 & #2 - 3rds is 3rds is 3rds... The only parameter shifting balance towards Peanut as being preferred - is if deco gas is not in the basin... If you do NOT have deco gas - you will want the final shallow exit the Peanut profile provides (say that 3 times fast...)....

But I'm also leaning heavily towards path of most recently known egress...

Marcie,

Tim (netmage) and I had a rousing discussion about this, we just did a 3 hour dive in Peacock today . . . it continues to put the "what do we do if" scenarios as part of our dive planning. Thanks for the post !!

My gut reaction to the scenario is our training tells us to return to the known/verified/gas requirement exit.

My real world response (only because we dive this cave so often) would be to get to Olsen, if Olsen was not available, get to Pot Hole.

switch to the other tank and exit.

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Originally Posted by Tegg

switch to the other tank and exit.

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Tim says I can do this :)~

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Originally Posted by netmage

I don't agree with, or understand the "might be past your available gas" comment.... 3rds is 3rds is 3rds...

I havn't been to Olsen lately - last time I recalled - I thought the sink was visible from the Crossover jump... so from that perspective - I would consider it verified and egress there. Knowledge of the cave comes to bear here. I may have to look tomorrow - on the map it looks further...

I'm also w/ Rob - when calc'ing gas we round down, so there is always a little gravy.

On points #1 & #2 - 3rds is 3rds is 3rds... The only parameter shifting balance towards Peanut as being preferred - is if deco gas is not in the basin... If you do NOT have deco gas - you will want the final shallow exit the Peanut profile provides (say that 3 times fast...)....

But I'm also leaning heavily towards path of most recently known egress...

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Olsen is about 100' from the Crossover jump and I've never been able to see it from there.

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Originally Posted by Tegg

switch to the other tank and exit.

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Gotta love sidemount!

If I remember correctly, the line arrows at the jump point to the nearest exit, Olsen. Head for Olsen. I never dive a known, popular, mapped system without knowing the the geography. Always stack the cards in your favor, not Murphy's. That is where all the hard work of the cartographers pays off. One can see the Olsen exit from the end off the line, at least during the daylight hours.

Dale

Yes, the end of the line ends in OW at Olsen, but the natural light from Olsen cannot be seen from the Crossover line. Cartographer or not, I am not going to trust a line arrow if I've been that way. While at Peacock the line arrows on the gold lines are marked with distances, that isn't the case in all systems. I've been on lines in JB where the line arrows point deeper into the system. Following the line arrows adds an additional 500' or more of passage. It makes sense there, though, because coming the way I came from cannot be exited by someone in backmount. I would be hesitant to use Olsen as an emergency egress unless I've been there that day, or even possibly within the past week. The opening from the passage to the basin is small enough that a small cave in could make it impossible to pass through and now you've just added a couple of hundred feet more to your exit and raised your stress level.

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Originally Posted by Tegg

switch to the other tank and exit.

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Exactly

tim, i wanted to head off someone saying that if the pothole leg of the circuit was a bit longer or deeper, you'd hit thirds from that side before you reached your cookie. what i was trying to say was that if you had some super-sensitive way to read every psi, you might have broken thirds to get to your cookie, but that in reality reading an spg in 100s you would not have.

What you have illustrated is that 3rds may not conservative enough as a gas planning rule, especially in low flow systems like Peacock.

Where's Ainslie? He must be busy or I would have expected him to chip in by now...

Andy

We had this scenario in our C2 course, and one buddy turned the dive right after the cookie and got a stern lecture (underwater) from the instructor. Once you pass the cookie you are supposed to be committed to exiting on the other side of the circuit.

In reality, if the cookie was substantially closer to the entrance of the circuit and the issue occurred right after the cookie, and we hadn't started pulling gear (other than the cookie), and I knew that we hadn't passed thirds on the penetration side, then I would consider turning it as an option -- but it would need to be obviously a better choice, and not require a not of debate underwater. The closer the cookie is to the midpoint, and the further the problem occurs after the cookie, the more we're simply committed to exiting the other side.

Excluding this kind of massive hypothetical, the point of picking up the cookie is to commit to the circuit and exiting the other side. That means that you have to rapidly go from the whole team being okay, to the whole team being in a world of hurt in a hurry -- and those kinds of situations are very unlikely. In that kind of situation, your training becomes secondary to being able to draw on experience and adaptability. If you really lost a burst disc, did you just create a huge mess in the cave? How did you exit that mess? In the confusion did you exit the silt cloud towards your entrance so that now your preferred exit on the circuit is on the other side of a huge mess? Might be better not to go back into the mess just to complete the circuit if you're still closer to your entrance -- sure. I'm not going to armchair quarterback anyone who really gets into a situation with that quantity of soiled underwear and manages to get out of it.

But you have to be careful in confusing yourself with hypotheticals that are highly unlikely to occur, which then cause you to have poor reactions for the more likely scenarios. The 99% most likely scenarios are that turning and swimming towards your original entrance on a circuit is a really bad idea past the halfway point, and that is more likely to get you killed. So the cookie means that you need to focus on committing to the other exit. It is much more likely that holding open the option of running for your original entrance on a circuit is going to confuse you and kill you, than it is going to save you from some bizarre hypothetical accident right in the middle of the circuit after picking up the cookie.

"switch to the other tank and exit."

Yes that is my choice also (independent backmount).


But assuming full gas loss of both (manifolded) tanks - right at thirds in both directions - and facing an air sharing exit... In a hypothetical situation where there isn't enough extra efficiency to squeeze out of the dive then there is likely no way the two divers can share air to either of the planned exits. Lost all gas on one diver - unless weighted properly for zero gas in tanks many divers in that situation would be buoyant. They barely made it from either direction when swimming each separate and weighted normally - now floating, excited, tied together with a 7' hose, and already "past thirds" by a bit. ---- Then Olsen would be the best choice.

If Olsen wasn't an option divers would be depending on flow, efficiency and luck to make it to Peacock by either route. But once past the cookie - and thirds - continuing in the planned direction to the exit would be the default (shouldn't require discussion). Pot Hole is a terrible option for trying to surface but maybe their best hope. Maybe better handholds for pull-and-glide on the Pot-hole line for a more gas efficient exit than pure swimming... but with both divers tied together "extra efficiency" is a vain hope at best.

Being weighted properly would obviously be a good idea. I think both "buoyant Out-of-Air diver" situations I'm thinking of were with Aluminum tanks - steel tanks less of a problem for most. But with Aluminum tanks actually wearing enough lead to be neutral with empty tanks would actually be important in that situation.

Sidemount or independents offers additional redundancy vs the "Completely out of air" situation. The "Completely out of air" with a manifold situation is pretty unlikely anyway. Sidemount or independents you'd have to postulate both regulators failing simultaneously - and even then you can still get to the gas.


If the system were significantly deeper then deco gas might become an issue. Olsen might get one alive to an exit but with insufficient gas remaining to complete deco. Bent would be better than dead - but if the gas situation were less obviously dismal to reach the original planned exit(s) taking a chance on the farther exit starts looking more attractive.

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Originally Posted by RN

None of the above. I don't push my gas management that much. The most I'll push anything is 1/3s + 100.

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That would help (ALOT! - 1400 out vs 1100 in!) but for two divers exiting together shared gas in the extreme proposed hypothetical scenario and the other issues it still might not be enough.


One of the issues I was thinking was that pre-dive planning discussing the potential exit points for various points of the dive would likely point out the need for more gas on the dive BUT I realized that you wouldn't really know in this situation how tight the gas was until you were actually in the situation:

You set up the dive to thirds on the one side and exit. You come back and dive to thirds, if you hit thirds before the cookie you turn if you hit the cookie first you continue. But you see the cookie ahead you go forward to get it and you are already at/past your planned turn gas - you'd find out really only once you were already in the situation.

It has never made much sense to me to set up a circuit like this anyway. You can dive it on one side - and return. You can dive it on the other side - and return. You see both sides going in and coming out.

Instead as a circuit/traverse, in order to "prove" it can really be done you set up one side do the other, don't see the exit on the 2nd side possibly leave a cookie stuck in the middle where you couldn't actually reach it as you thought. And then unless you did a visual jump you have to go back on another dive to get the reels/cookies you left in the cave.

On a double gap-jump like that a circuit/traverse seems like a silly idea to me. If the circuit/traverse has just a single jump and the jump can be set up with the cookie as the "halfway" marker with continuous lines to both exits and so there isn't any reel left in to have to retrieve later. Or if the whole circuit/traverse can be done thirds with no gaps it doesn't require all the setup and mess.

I'd rather just do the dives from each end and skip the extra work and risks.

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Originally Posted by RN

None of the above. I don't push my gas management that much. The most I'll push anything is 1/3s + 100. So if I start with 3600, my turn pressure is 2500 leaving me 1100 for exit and 1400 for emergencies. I do this in systems like JB or Devil's. In a system like Peacock, Twin, Hole in the Wall, I dive 1/3s + 200...3600 starting, 2600 turn, 1000 for exit, 1600 for emergencies. If it's a new system or involves advanced stuff, like really tight sidemount passage, I dive 1/4s. This is also what I teach my students because of the possibility of something like what you describe in your scenario. If you need more gas to do the dive, then get larger cylinders or bring a stage.

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+1
I don't understand why some people will push to thirds or even beyond (I know I know it's hypothetical). Thirds is NOT conservative enough.

One thing nobody has mentioned is the inevitable fact that both of your SAC rates are going to jump way up if something like that happened.

FWIW, in the *real* Peacock, Olsen would be the best bet, because there is so much traffic, and line maintenance there that the line would probably be in good shape. I wouldn't make that assumption in less traveled caves.

Like Tegg etc., I am sidemount, and odds of loosing all my gas would be slim. Like RN etc., I never push my gas to thirds.

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Originally Posted by FW

I never push my gas to thirds.

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That's cuz you dive with me, and I have a worse SAC rate than you! ;)

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Originally Posted by Gary

That would help (ALOT! - 1400 out vs 1100 in!) but for two divers exiting together shared gas in the extreme proposed hypothetical scenario and the other issues it still might not be enough.

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That's my high flow gas management. In low flow, it's 1600 out vs 1000 in.

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Originally Posted by FW

One thing nobody has mentioned is the inevitable fact that both of your SAC rates are going to jump way up if something like that happened.

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In most cases yes. However, I've had stuff happen and my response always ends up in a lower consumption rate. It's pretty much the only time I intentionally skip breathe.

With all the attention always paid to the "one buddy suddenly out of air at thirds" situation and 2 buddies coming back on a single air supply it is worth reminding everyone that although it gives a concrete reason that makes sense for creating "thirds" as a rule in actuality it never happens that way.

Generally sudden equipment failure / air loss is not involved in fatal accidents. Most fatalities involve situations where persons violated thirds in some way - or that some other accident occurred that thirds was not enough gas to solve the problem.

While a lot of attention is paid to the manifold/non-manifold issue I don't think it has ever been an issue either way in a fatal accident.

Thirds simply provides a sufficient buffer for "most" accidents. There are however, examples of fatal accidents where quarters, fifths, or even sixths proved insufficient.

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Originally Posted by Gary

With all the attention always paid to the "one buddy suddenly out of air at thirds" situation and 2 buddies coming back on a single air supply it is worth reminding everyone that although it gives a concrete reason that makes sense for creating "thirds" as a rule in actuality it never happens that way.

Generally sudden equipment failure / air loss is not involved in fatal accidents. Most fatalities involve situations where persons violated thirds in some way - or that some other accident occurred that thirds was not enough gas to solve the problem.

While a lot of attention is paid to the manifold/non-manifold issue I don't think it has ever been an issue either way in a fatal accident.

Thirds simply provides a sufficient buffer for "most" accidents. There are however, examples of fatal accidents where quarters, fifths, or even sixths proved insufficient.

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Well said !

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Originally Posted by Gary

With all the attention always paid to the "one buddy suddenly out of air at thirds" situation and 2 buddies coming back on a single air supply it is worth reminding everyone that although it gives a concrete reason that makes sense for creating "thirds" as a rule in actuality it never happens that way.

Generally sudden equipment failure / air loss is not involved in fatal accidents. Most fatalities involve situations where persons violated thirds in some way - or that some other accident occurred that thirds was not enough gas to solve the problem.

While a lot of attention is paid to the manifold/non-manifold issue I don't think it has ever been an issue either way in a fatal accident.

Thirds simply provides a sufficient buffer for "most" accidents. There are however, examples of fatal accidents where quarters, fifths, or even sixths proved insufficient.

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I recall reading about an incident in one of Sheck's books where there was a sudden complete gas loss at maximum penetration and he and his buddy barely made it back to their stage bottles and out alive. While this is a rare event, it's enough for me to not ever push air management all the way to 1/3s. An extra 100-200 psi isn't going to get me that much farther and can easily be compensated for with a stage bottle. No one ever died from having too much gas.

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Originally Posted by RN

....No one ever died from having too much gas.

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+1 !!

i was more interested in the routes & reasonings people would choose.

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Originally Posted by FW

One thing nobody has mentioned is the inevitable fact that both of your SAC rates are going to jump way up if something like that happened.

FWIW, in the *real* Peacock, Olsen would be the best bet, because there is so much traffic, and line maintenance there that the line would probably be in good shape. I wouldn't make that assumption in less traveled caves.

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I think that is Marci's point - if you are right at (or close to) thirds and one of you experiences a total gas loss, the theory that the other diver still has a third to get out and another third to get the OOG diver out is just that - a theory. The reality is:

1. stress and an elevation on SAC rate,
2. sharing gas on a long hose,
3. the high probability of large amounts of silt when the gas venting from a ruptured burst disc a) slams the OOG diver into the silt in the low tunnel and b) percolates more silt off the ceiling,
4. the possibility of being off the line and having to find the line before you start to exit, and
5. if you do not immediately get on the line before the viz goes and lose the line, when you find the line will you immediately know which way is out?

In light of that reality, it is almost certain that "thirds won't be enough gas to cut it in terms of either exiting as planned or returning to your starting point if both require virtually a full third under ideal conditions.

If you were to end up in that situation, Olse is in my opinion the best bet in the theoretical Peacock. It is perhaps 250 ft from the middle of the cross over tunnel, compared to about 1150-1200 feet to P1 via peanut and about the same via the deeper Olsen/Pothole side. Olsen has been open for decades and the probability of a geologic event is small - smaller than the probability of thirds leaving you a couple hundred feet short of P1 by either of the other routes. And, if the very unlikely event of a collapse did occur, you still have pothole and that buys you another 400 feet or so, plus you still have 200' in the bank even if the Olsen attempt fails.

The preferrable thing is to avoid that situation in the first place by not pressing thirds. When you do the math, turning 100-200 psi early costs you very little in terms of penetration, but leaves you 200-600 psi more gas in reserve (just 100 psi less penetration gas means 21.6 cu ft more reserve gas in double 95's or 130s, 200 psi increases this to 43.3 cu ft additional reserve.)

Other alternatives are a three person team, using a stage on the dive if you have a two person team to maintain a greater back gas reserve, or taking a buddy bottle as an additional reserve on a two person team. All of those options add more reserve gas and allow you to make the dive in far greater safety regardless of what happens.

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Originally Posted by RN

I recall reading about an incident in one of Sheck's books where there was a sudden complete gas loss at maximum penetration and he and his buddy barely made it back to their stage bottles and out alive. While this is a rare event, it's enough for me to not ever push air management all the way to 1/3s. An extra 100-200 psi isn't going to get me that much farther and can easily be compensated for with a stage bottle. No one ever died from having too much gas.

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I think anyone who disagrees with your post is 100% WRONG.
Well said.

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Originally Posted by RN

None of the above. I don't push my gas management that much. The most I'll push anything is 1/3s + 100. So if I start with 3600, my turn pressure is 2500 leaving me 1100 for exit and 1400 for emergencies. I do this in systems like JB or Devil's. In a system like Peacock, Twin, Hole in the Wall, I dive 1/3s + 200...3600 starting, 2600 turn, 1000 for exit, 1600 for emergencies. If it's a new system or involves advanced stuff, like really tight sidemount passage, I dive 1/4s. This is also what I teach my students because of the possibility of something like what you describe in your scenario. If you need more gas to do the dive, then get larger cylinders or bring a stage.

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Originally Posted by apitkin

What you have illustrated is that 3rds may not conservative enough as a gas planning rule, especially in low flow systems like Peacock.

Where's Ainslie? He must be busy or I would have expected him to chip in by now...

Andy

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He's here...

I just did a dive in Ginnie on CC where I reserved 400 cubic feet to travel 4800 feet. I made it out with under 100 cubic feet left. In theory, I used about 3 times the amount of gas that I should have. It's a long story why, involving some restrictions that took longer to get past than I was expecting, an unintended jump and a flooded rebreather... but that's exactly the sort of hellish scenario that reserves are designed for. An even more amazing statistic - of those 300 cu ft used, I used 200 cu ft "navigating" (poorly, with a very screwed up head) from 4800 ft back to 3200 ft.. THe next 100 cu ft got me to the exit - and even that was due to a ridiculous SAC rate under pressure.

Let me emphasise this - if I had dived with only double the gas theoretically needed to exit, I would have run out somewhere around the Henkel, and drowned. If I had dived with triple the reserves, I would have barely made it. I NEEDED a 4x reserve.

My (somewhat misunderstood) philosophy is to a) work out the bare minimum needed to exit, and b) add whopping reserves onto that bare minimum. In this case, I had 4x the reserves theoretically needed (or, in OC terms, I was diving fifths) and it was nearly not enough.

Ah, the naughty word censors... doo-dah happens. Prepare for it.

BD, I think what a lot of people are telling you is that it's not a matter of routes, its a matter of never going anywhere near thirds in a low flow scenario like Peacock. SPG errors are one of many very good reasons NOT to go to thirds.

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Originally Posted by aainslie

...I just did a dive in Ginnie ....

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Did you get a chance to test the new camera?

PS, I am glad you made it out OK. It does show that some people aren't using nearly enough bailout :roll:

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Originally Posted by BabyDuck

i was more interested in the routes & reasonings people would choose.

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Okay. Go to Olson. No other option would be considered.

A diver new to the Peacock system may choose one of the other options, but I have almost a hundred dives there, and I've studied the map since I was a cavern diver.

While we're at it, I've always had a problem with "the thumb." People reach thirds and "give the thumb." But the thumb and the finger twirl mean two different things, and I make sure everyone I dive with knows the difference.

The finger twirl means to turn around. No emergency, just turn around and go out about the same as you had come in. If you lolligagged on the way in, you can lolligag on the way out (although not quite as much lolligagging should happen on the way out).

A thumb means "leave now." Although not necessarily a full-fledged emergency, there's no wasting time getting out. It usually means the diver is not 100% comfortable and wants to be at the surface without much delay.

Systems such as Jackson Blue, with one and only one exit, mean go straight out without delay. Systems such as Peacock mean an alternate exit might be considered. But within reason. If we're a little closer to Olson than Peacock 1 and I get a thumb, we're still exiting where we came in. But in your example, where you KNOW you're way closer to Olson than Peacock 1, we're coming out Olson.

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Originally Posted by aainslie

It's a long story why, involving some restrictions that took longer to get past than I was expecting, an unintended jump and a flooded rebreather... but that's exactly the sort of hellish scenario that reserves are designed for. An even more amazing statistic - of those 300 cu ft used, I used 200 cu ft "navigating" (poorly, with a very screwed up head) from 4800 ft back to 3200 ft.. THe next 100 cu ft got me to the exit - and even that was due to a ridiculous SAC rate under pressure.

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I'd be interested in hearing more details regarding this dive... if you don't mind sharing them. (Purely from a curiosity standpoint and not from a critical one.)

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Originally Posted by Slüdge

.... Systems such as Peacock mean an alternate exit might be considered. But within reason. If we're a little closer to Olson than Peacock 1 and I get a thumb, we're still exiting where we came in. But in your example, where you KNOW you're way closer to Olson than Peacock 1, we're coming out Olson.

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Another "forgotten" hand signal is the thumb, and index finger. It is usually used to mean "that way is out". I would hope nobody would ever need to ask that. In the above senario it could be used to say I need to go out fast, and Olsen is closer. It could also be used to say I want to leave now, but I have gas to get back to P1 without delay.

FWIW, I tried that signal with the buddy that was trying to go the wrong direction, but she didn't seem to understand it.

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Originally Posted by RN

I recall reading about an incident in one of Sheck's books where there was a sudden complete gas loss at maximum penetration and he and his buddy barely made it back to their stage bottles and out alive. While this is a rare event, it's enough for me to not ever push air management all the way to 1/3s.

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Actually that is one of my favoite stories - one that actually does show how independent/sidemount advantage over manifold (the gas loss from both tanks was only posiable due to the manifold).

But IIRC while they were at "maximum penetration" they had turned early on gas. They had more than thirds but ran out before reaching stages (due to bouyancy issues and air sharing). Even after reaching stages they nearly ran out of gas again even though they both had full supplies at that point.

If they had been at thirds when the the accident happened they almost certainly would not have made it. :hang While if they were diving independents/sidemount it would have been a non-event - not even a story worth including.

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Originally Posted by aainslie

He's here...

I just did a dive in Ginnie on CC where I reserved 400 cubic feet to travel 4800 feet. I made it out with under 100 cubic feet left. In theory, I used about 3 times the amount of gas that I should have. It's a long story why, involving some restrictions that took longer to get past than I was expecting, an unintended jump and a flooded rebreather... but that's exactly the sort of hellish scenario that reserves are designed for. An even more amazing statistic - of those 300 cu ft used, I used 200 cu ft "navigating" (poorly, with a very screwed up head) from 4800 ft back to 3200 ft.. THe next 100 cu ft got me to the exit - and even that was due to a ridiculous SAC rate under pressure.

Let me emphasise this - if I had dived with only double the gas theoretically needed to exit, I would have run out somewhere around the Henkel, and drowned. If I had dived with triple the reserves, I would have barely made it. I NEEDED a 4x reserve.

My (somewhat misunderstood) philosophy is to a) work out the bare minimum needed to exit, and b) add whopping reserves onto that bare minimum. In this case, I had 4x the reserves theoretically needed (or, in OC terms, I was diving fifths) and it was nearly not enough.

Ah, the naughty word censors... doo-dah happens. Prepare for it.

BD, I think what a lot of people are telling you is that it's not a matter of routes, its a matter of never going anywhere near thirds in a low flow scenario like Peacock. SPG errors are one of many very good reasons NOT to go to thirds.

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Thanks for this great example of why 1/3s is not enough!!!

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Originally Posted by Sludge

While we're at it, I've always had a problem with "the thumb." People reach thirds and "give the thumb." But the thumb and the finger twirl mean two different things, and I make sure everyone I dive with knows the difference.

The finger twirl means to turn around. No emergency, just turn around and go out about the same as you had come in. If you lolligagged on the way in, you can lolligag on the way out (although not quite as much lolligagging should happen on the way out).

A thumb means "leave now." Although not necessarily a full-fledged emergency, there's no wasting time getting out. It usually means the diver is not 100% comfortable and wants to be at the surface without much delay.

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Exactly!!! I teach my students about this difference. My first sidemount passage in JB had me coming back in zero visibility. I came up to the restriction and hit rock. I backed up and changed direction again, and hit rock again. This happened 3 times before I found the hole I was looking for. Keep in mind I had the line in my hand the entire time! When I popped out I signaled my wife with the thumb. Our usual exit consists of learning what the cave looks like from that direction and also looking for side passages for future dives. We still always get out with close to 2000psi. Well, she proceeded to do this. I signaled a thumb again and she signaled back and continued a leisurely pace out. I finally got in her face and signaled one more time. She got it that time. Once back at the surface we decided a twirly finger is the signal for a leisurely exit and a thumb means it's time to GTFO. Unfortunately, there are divers out there that think the thumb is the only appropriate turn signal, instructors included.

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Originally Posted by Gary

Actually that is one of my favoite stories - one that actually does show how independent/sidemount advantage over manifold (the gas loss from both tanks was only posiable due to the manifold).

But IIRC while they were at "maximum penetration" they had turned early on gas. They had more than thirds but ran out before reaching stages (due to bouyancy issues and air sharing). Even after reaching stages they nearly ran out of gas again even though they both had full supplies at that point.

If they had been at thirds when the the accident happened they almost certainly would not have made it. While if they were diving independents/sidemount it would have been a non-event - not even a story worth including.

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It's been years since I read the account. Thanks for the clarification. It brings across the point even better!

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Originally Posted by KarsticGator

I'd be interested in hearing more details regarding this dive... if you don't mind sharing them. (Purely from a curiosity standpoint and not from a critical one.)

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I've offered it as an NACD article. We'll see if they want to publish it. if not I'll put it up here. Give me a couple of weeks on this one.

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Originally Posted by RN

Exactly!!! I teach my students about this difference. My first sidemount passage in JB had me coming back in zero visibility. I came up to the restriction and hit rock. I backed up and changed direction again, and hit rock again. This happened 3 times before I found the hole I was looking for. Keep in mind I had the line in my hand the entire time! When I popped out I signaled my wife with the thumb. Our usual exit consists of learning what the cave looks like from that direction and also looking for side passages for future dives. We still always get out with close to 2000psi. Well, she proceeded to do this. I signaled a thumb again and she signaled back and continued a leisurely pace out. I finally got in her face and signaled one more time. She got it that time. Once back at the surface we decided a twirly finger is the signal for a leisurely exit and a thumb means it's time to GTFO. Unfortunately, there are divers out there that think the thumb is the only appropriate turn signal, instructors included.

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I use the same signals and learned an important lesson on a dive with regular team members. We had been diving for a few days with the same group of people. On this day another of our regulars joined us fresh out of a class (Apprentice IIRC). We were a little complacent in our dive planning and did not go over the finger swirl and thumb signals. The diver out of the class gave the thumb signal and was questioned to ensure he meant thumb. In his class they had only used the thumb to turn the dives and he had forgotten about the finger twirl. This resulted in added stress for everyone in the team with each of us wondering who was having a problem and what it was. We all made mistakes that day and allowed complacency to enter our diving from familiarity of us diving together.

Bobby

A large part of the thumb versus twirly finger problem is cultural.

How many times do you hear people say "we thumbed the dive" when talking about a normal "turned the dive" situation? "Thumbing" a dive has become common slang for turning the dive and as such has lost much of its original meaning and all of it's distinction as an "EXIT NOW ASAP" signal. We all play a part in correcting or continuing that misperception of the signal by our actions in either clarifying it, or not, when we see it and hear it.

I don't think we have to reserve the thumb for full on emergencies, by any means, but it should clearly convey a "we need to leave right now and proceed out with no dicking around" message.

I like the "twirl" for turn and thumb for get the heck out of Dodge, but I have been specifically taught not to use the two different signals. It seems as though there ought to be some easy way for a diver to convey an urgent exit, though. Although most problems will be apparent to the team, some may not be, and specifically any relating to an individual diver's physical state.

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Originally Posted by aainslie

Let me emphasise this - if I had dived with only double the gas theoretically needed to exit, I would have run out somewhere around the Henkel, and drowned. If I had dived with triple the reserves, I would have barely made it. I NEEDED a 4x reserve.

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First, let me say that I agree thirds is unlikely to be sufficient in a catasrophic gas loss at maximum penetration. Divers should be able to calculate theoretical minimum reserves and add to them based on various factors.

However, your dive seems to be a prime example of why conventional gas planning does not translate to closed circuit rather than why conventional gas planning is insufficient. Without knowing the details of the dive, it seems like several exacerbating factors should be considered that would cause a diver to add reserves whether planning an OC or CC dive. You mentioned complex navigation, difficult restrictions, solo (?) etc. You obviously recognized those difficulties and planned accordingly.

My point is that an OC dive team planning a relatively simple dive in Peacock would not require the same reserves. The real art to dive planning is recognizing the exacerbating factors and planning accordingly.

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Originally Posted by LCF

I have been specifically taught not to use the two different signals.

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I can guess. The problem with using two different hand signals for two different situations would be...

Glad to find more finger twirlers amongst cavers. I was starting to think cave community was mainly thumbers because so adamant has been the resistance if not ridicule when bringing this up pre-dive. I am always sure to ask what people use for turning, especially because my first cave instructor was a thumber. I have always been a turner not a thumber but I’ve found that a lot of cavers prefer the unequivocal thumb. I will do what is agreed but I can’t help it that I always associate thumb with ‘out NOW’, and get slightly irritated if there are delays without explanations after it is presented.

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Originally Posted by alias

I will do what is agreed but I can’t help it that I always associate thumb with ‘out NOW’, and get slightly irritated if there are delays without explanations after it is presented.

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It's even more annoying the other way - when you thumb a dive to exit NOW and team members start dicking around and delay the exit.

If anyone insists on a thumb, they're going to have a hard time catching me exiting. :rollguy

To me it is important to use the two different signals as they are meant to be. One dive a while back I was with a dive buddy and he turn the dive (twirled finger), so I answered and we started out. I made a couple of stops and he became a little antsy and gave the thumbs up signal which changed the tone of the dive. Nothing serious but a he had become very anxious being a newbe cave diver and wanted the hell out of Dodge.

I have thumbed very few dives over the years and reserve the thumb for what it was intended for.

Dale

Easy, Get your butt out of the cave at the nearest exit, If you did what your suppose to an studied the map you should know where that is even if it's the first time in the cave. There is only one real emergancy in a cave. That's No gas. The rest are just things to deal with.

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Originally Posted by Slüdge

If anyone insists on a thumb, they're going to have a hard time catching me exiting. :rollguy

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I'd think it'd be the opposite. If someone gives me the thumb, I'm going to be on them like the proverbial "white on rice" to ensure I'm available to help with whatever prompted thumb, should it get worse.

And yep, I go over the twirl vs thumb before a dive with a new buddy. If I have any doubt as to a possible problem when I get the thumb, I return the thumb and as I'm turning (not wasting any time!), I also get beside the buddy and point at them, followed by the OK...as in "you ok, bud?"

Okay, Shirley, I guess I didn't make myself clear. This would be for someone who insists that a finger twirl is an unacceptable signal, and a thumb is the only way to signal turning on thirds.

I would make sure things were indeed fine, then make a beeline for the exit.

(That was me being a DB. Get it?)

I'm a finger twirler. If someone gives me the thumb I'm going to be pretty concerned about identifying the problem that lead to the emergency so I can account for it on the exit. (Do I put them in front to light the way for them and find/communicate with them? Do I need to worry that their one remaining regulator could go and I should be extra handy? Are they cold/confused/gonna pass out? Or a emphatic turn on gas remaining?)

Yes, thumbs-up means "EXIT" no question on that - but if they don't say what is wrong (and I can't see "it" for myself) I will probably ask.

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Originally Posted by alias

Glad to find more finger twirlers amongst cavers. I was starting to think cave community was mainly thumbers because so adamant has been the resistance if not ridicule when bringing this up pre-dive. I am always sure to ask what people use for turning, especially because my first cave instructor was a thumber. I have always been a turner not a thumber but I’ve found that a lot of cavers prefer the unequivocal thumb. I will do what is agreed but I can’t help it that I always associate thumb with ‘out NOW’, and get slightly irritated if there are delays without explanations after it is presented.

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The problem is a lot of the old school instructors out there teach it and don't think anything else is acceptable. They're still cranking out students and so that's what you get. It's how I was taught and what I did until my incident. Now I twirl and rarely thumb. And I teach my students the same. I did have one student go on to another instructor when I told him he wasn't ready for the next level and he told me he was chastised for twirling. It's just the way it is. I guess until they're in a situation where it makes a difference they'll keep thumbing all dives. I even tell my students if they thumb it that means no drills. But it doesn't mean they can thumb every dive! ;)

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Originally Posted by RN

I even tell my students if they thumb it that means no drills.

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I was actually going to say this in my post. It took me some time to get used to the fact that drills still happened when someone had thumbed, even when I knew it was coming. Although, I have to say the only time we truly hit 6ths ahead of schedule (first time in the Ear not quite sticking to the riding lane as per plan), we did skip the drills because we had quite enough to debrief already :D

With the guys I normally dive w/ we use the finger twirl instead of a thumb. Recently, we also adopted a light signal version of this, which is an "OK" signal with the light, but on the ceiling instead of the floor. Basically, when it's time to turn, an attention signal, followed by a circular signal on the ceiling. We use ceiling instead of the floor to avoid confusion betwen "turnaround" and "OK". Obviously this requires knowing your team, and may not work in all caves, but just an idea that works for us.

John

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Originally Posted by sskasser

I'd think it'd be the opposite. If someone gives me the thumb, I'm going to be on them like the proverbial "white on rice" to ensure I'm available to help with whatever prompted thumb, should it get worse.

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Same theme here. Twirly finger = follow at a reasonable/normal distance, thumb = follow right behind the team member.

hey, john, i like that. what do you think, larry?

then again, at least with a turn or a thumb, the lead has to turn around anyway, so i guess it doesn't matter. i get irked at myself, though, when i've turned around because i was overly reading a non-signal. (not irked at my buddy, he's not usually a thrower of non-essential light.)

As with any light signal, clarity is important, so it would have to be round, on the ceiling and done in a slow and deliberate manner to ensure it is not confused with another signal in order to be a viable option, and it would be limited to the lead diver, who will be turning around anyway. In order to be used by the trailing diver, it would have to be preceded by an attention signal, and in that case the lead diver is going to turn around anyway, so it offers no real advantage over the hand signal, unless someone on the team is nearsighted qnd can't see the hand signal, and that is another problem that shoudl be addressed on its own.

My buddy and I twirl, the thumb means the dive is over, we are leaving NOW. The twirl means (to us) turn around, head toward the exit but the dive is not over and if one of us wants to "poke around" then the twirl allows this. If a thumb is thrown, no "poking around" head for the exit now.

The thumb usually gets thrown on the way toward the exit after the twirl just to make a defined point the dive is over.

To me a a twirl is simply "let's turn around" - we could be continuing the dive, just getting out of a particular passage, etc. A thumb up on the other hand would be an unequivocal "let's get out". If I wanted to get out faster I would signal for my buddy to hurry up. A twilrl is somewhat dubious and does not indicate reaching dive limits (be it gas, depth, distance, whatever).

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Originally Posted by NEON

To me a a twirl is simply "let's turn around" - we could be continuing the dive, just getting out of a particular passage, etc. A thumb up on the other hand would be an unequivocal "let's get out". If I wanted to get out faster I would signal for my buddy to hurry up. A twilrl is somewhat dubious and does not indicate reaching dive limits (be it gas, depth, distance, whatever).

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i Think I might agree wth you - partially - but you are sending a bit of a mixed message with the dubious comment. The twirly finger is indeed much more of a flexible signal with regard to why we are turning, but the meaning is crystal clear taken in the context in which it is given.

For example, we may do a dive with the intent to explore a side tunnel on the way in before continuing up the main tunnel to the turn point of the dive. As long as all divers understand the plan, then getting the twirly finger in the side tunnel just signifies ending that portion fof the overall plan and returing to the main line.

Then, at that navigational decision at the mainline, everyone is going to OK the navigational decision to continue farther in the main tunnel after checking gas and deco status to ensure it is worth the effort. If all are in agreement to proceed, you proceeed until you get a twirly finger for gas. If someone does not OK the decision to proceed, they can give the twirly finger to signal "turn the dive" or perhaps give a "thumb" to indicate the need to exit with no delay if the situaion warrants.

In short, with proper dive planning, proper SA and when the signal is taken in the context of the dive the twirly finger will not be ambiguous or dubious. If it is, the diver has far larger issues as a diver or within the team that need to be resolved and a "thumb" will not solve that larger problem.

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Originally Posted by NEON

A twilrl is somewhat dubious and does not indicate reaching dive limits (be it gas, depth, distance, whatever).

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I agree with DA - if someone wants to turn around, the reason doesn't enter into the equation. Just whether we exit at a leisurely pace or quickly.

What has been working well for us is a twirly finger to simply turn around, but not end the dive.

A twirly finger followed by a finger point with a raised thumb with the index finger pointing in the direction of the exit means we are ending the dive according to plan. It might be gas, geography, time, or just something like slight tiredness or similar, but the twirly then finger point means no worries, lets enjoy the exit, but we are now on the exit phase of the dive.

A thumb means there is some compelling reason to end the dive now, not as part of the original plan, or if we are turning to exit as part of the plan, there is some compelling reason that the exit should be with reasonable haste, no farting around, lets go!

All of the signals are returned in kind to indicate that we understand and are in agreement. The twirl then point, like the thumb, are not really up for negotiation, they are just different to indicate how we should treat the exit.

Mark Vlahos

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Originally Posted by BabyDuck

do you:
1) keep going to complete your circuit. it is verified line, and shallower than turning around, but will be at the ragged edge of your gas.
2) turn around and go back out the way you came. it is also verified line, but a bit deeper, and might be past your available gas. you could possibly go out pothole. that line is unverified.
3) turn around and head for olsen. you would go back over your jump then turn left instead of right. you have been to olsen before, but not on this trip/not for several months. it is a closer exit by far, but the line is unverified by you recently.

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Originally Posted by Tegg

switch to the other tank and exit.

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Small add on for the sidemount divers and other independent tank types:

Your buddy has a manifold and he/she has the out of air accident. :o

Go:

As it is my natural instinct as a man, head for the nearest hole would be my call.

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Originally Posted by Herbie

As it is my natural instinct as a man, head for the nearest hole would be my call.

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ahem and add a twirly finger ...

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Originally Posted by Slüdge

I agree with DA - if someone wants to turn around, the reason doesn't enter into the equation. Just whether we exit at a leisurely pace or quickly.

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How so? What would make yo assume that I'd want to exit - may be I just want to look at a potential lead we just passed by???

Then you don't give a turn around signal. You do the two-finger point-at-your-eyes signal (meaning "look at") and then point at the potential lead.

That could be interpreted as if I am asking you to take a look at something. I think that the original and the most appropriate meaning of the twirling finger is to "turn around" and does not necessarily mean "let's exit".

I believe that my interpretation is the one described in the NSS-CDS Cave Diving Manual as well as in the Cave Diving Communications by J.Prosser & H.V.Grey. I suggest that you take a look at the example that J.Prosser uses to illustrate the use of the two signals.

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Originally Posted by NEON

That could be interpreted as if I am asking you to take a look at something. I think that the original and the most appropriate meaning of the twirling finger is to "turn around" and does not necessarily mean "let's exit".

I believe that my interpretation is the one described in the NSS-CDS Cave Diving Manual as well as in the Cave Diving Communications by J.Prosser & H.V.Grey. I suggest that you take a look at the example that J.Prosser uses to illustrate the use of the two signals.

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He is right, the "twirly" just means "turn around", not necessarily "exit".

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Originally Posted by FW

He is right, the "twirly" just means "turn around", not necessarily "exit".

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Absolutely - you have to take most signals in the context of the dive and apply come common sense and the twirly finger "turn around" signal falls in that category. The "thumb" is in that sense properly regarded as an exception - it should mean "exit now" regardless of when or where it is given.

The "twirly" sign is not in the Cavern/Cave Diver Workbook 2005, 2006. Was it added later or was it obtained from the small book just for signals? Ok, some are saying to use the "twirly" sign to mean normal exit and others are using it to mean turn around. I was, noticed was, using the thumb to end all dives. If it was an emergency, then there would have been the added fast moving light signal. The worse the situation, the faster the light. This "twirly" sign can get confusing, can't it? I think that Helo Driver was using it when we were diving together and I had to ask for verification. Sorry friend, I get it now. Anyway, I rather like my old way...thumb only or light and thumb. I thought that everyone had those two down solid. So in the furture, I will go over signs and we will work it out together.

Actually, the best thing would be to discuss ALL hand signals during the S-drill.

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Originally Posted by TONY CHANEY

The "twirly" sign is not in the Cavern/Cave Diver Workbook 2005, 2006. Was it added later or was it obtained from the small book just for signals? Ok, some are saying to use the "twirly" sign to mean normal exit and others are using it to mean turn around. I was, noticed was, using the thumb to end all dives. If it was an emergency, then there would have been the added fast moving light signal. The worse the situation, the faster the light. This "twirly" sign can get confusing, can't it? I think that Helo Driver was using it when we were diving together and I had to ask for verification. Sorry friend, I get it now. Anyway, I rather like my old way...thumb only or light and thumb. I thought that everyone had those two down solid. So in the furture, I will go over signs and we will work it out together.

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It's not in any book. But as happens, things evolve. The issue I have with the thumb and light is that there isn't always an emergency, but sometimes it's just time to leave without sightseeing. That's what the thumb means to me. The twirly finger means let's turn around and do our usual slow exit.

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Originally Posted by Slüdge

Actually, the best thing would be to discuss ALL hand signals during the S-drill.

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While underwater?

The S-drill, or safety drill, encompasses all pre-dive discussion, not just practicing air-sharing.

Although some people call the air-sharing drill "the S-drill."

I agree with NEON. Since when did the thumb become an emergency signal? They are both useful signals but communicate different information. The finger twirl simply means "turn around" while the thumb means we have reached our predetermined limit (gas, time, etc.) and need to exit the cave.

I suspect that the finger twirl has caught on as a means of calling the dive because many divers are embarrassed to call a dive on gas. Since gas is typically what cave divers use to plan their dive limits the finger twirl allows them to call the dive without revealing that they have reached their turn pressure. For this reason alone, I think it is bad form to replace the thumbs up signal with the finger twirl.

Here's an example of how they can both be used effectively on a dive: Two divers approach a split in the passage with line going in both directions (a fork in the road if you will). After a brief consultation the divers decide to pursue the passage on the right. After about 200' one of the divers realizes they choose the wrong passage (for whatever reason) and gives their buddy the finger twirl to communicate that they want to turn around. Back at the intersection, they choose to pursue the left passage. After several hundred feet one of the divers reaches their turn pressure (or realizes that they have reached their turn time-either way, it doesn't matter) and gives their buddy the thumbs up to communicate that they have reached their turn pressure (or time). While they proceed to exit, there is no emergency and neither diver is alarmed. They proceed to the exit in a normal manner. If there had in fact been an emergency the diver would be much better served using an actual emergency signal and alerting their buddy to the problem. The thumbs up does not communicate enough vital information to serve as a useful emergency signal.

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Originally Posted by NEON

To me a a twirl is simply "let's turn around" - we could be continuing the dive, just getting out of a particular passage, etc. A thumb up on the other hand would be an unequivocal "let's get out". If I wanted to get out faster I would signal for my buddy to hurry up. A twirl is somewhat dubious and does not indicate reaching dive limits (be it gas, depth, distance, whatever).

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There's no embarrassment about turning a dive on gas. For me, the finger twirl usually means personal gas limits have been reached. The thumb means an expedited exit. It's not necessarily an emergency. I do this because I had a situation in which differentiating between a normal exit and an expedited exit was necessary. So, as a result, we came up with a solution for our issue.

I have "twirled" dives due to many things, like wanting extra time to negotiate restrictions, knowing there was silt behind us, wanting to check a lead, etc. It doesn't necessarily mean anyone hit gas turnaround.

There's no shame in "twirling" on gas. Dive with FW often enough and you get used to it :D The only shame to be had in reaching your turn pressure is if you DON'T turn the dive.

JCR, I don't entirely disagree, but again it is context that matters. If I give a thumb anywhere near max penetration it should be a lot more compelling than a twirly finger.

For example, we do a dive fairly far back into a cave, exploring a side passage, where we twirly finger to return to the main line and proceed farther into the cave, the twirly finger again to turn the dive on gas or perhaps deco time, then on the way out we make a leisurely exit, perhaps looking for new area to poke around on a subsequent dive, exploring the cavern on surplus gas, etc. The thumb if used at all on that dive, gets used then or at the end of the deco stop to indicate "let's go up now" - in that context it signals, we are done now and are going up now.

I contrast, if I use a thumb signal any significant distance into the cave, it means we exit NOW by the most direct route with no dicking around and implies that time is of the essence. The reason may be a gas problem, the need to turn and exit now due to accumulating deco, some type of equipment concern or maybe just a level of discomfort. It does nto have to be an emergency but it does convey a sense of urgency that a twirly finger does not. I agree you can communicate the nature of an emergency if one exits, and in some cases you clearly should, but in some cases what matters is to immediately initate the exit and if the situation is otherwise under control, wasting time communicating specifics may be counter productive.

What matters is that the team understands the signal and is able to read what the signal really means in the larger context of the dive, rather than making a black and white assumption or interpretation. If a diver needs black and white and is not able to maintain the SA or problem solving skills needed to connect the dots correctly, cave diving is probably not a sport he or she should continue doing.

When you look at the thumb as just a "turn the dive" signal then it actually has less meaning and clarity as there is no discrimination or reference to how we should turn the dive and exit the system.

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I also agree with the others that there is no shame in turning the dive, for gas or for other reasons. In fact, if you think there is shame in that, you should not be diving and I sure as hell do not want a diver who thinks that diving with me. If that is the case, then the odds are sooner or later, they are going to bust the gas plan or press on past their comfort level and either get us in trouble or lack their share of the team resources they were supposed to have if we got in trouble.

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Originally Posted by DA Aquamaster

I also agree with the others that there is no shame in turning the dive, for gas or for other reasons. In fact, if you think there is shame in that, you should not be diving and I sure as hell do not want a diver who thinks that diving with me.

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Please reread my post. I am not condoning this behavior, merely pointing out what I have observed. I agree, this is dangerous behavior and the reason I believe it is necessary to communicate unequivocally that you have reached your turn pressure. The twirly finger does not accomplish that effectively.

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I have "twirled" dives due to many things, like wanting extra time to negotiate restrictions, knowing there was silt behind us, wanting to check a lead, etc. It doesn't necessarily mean anyone hit gas turnaround.

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FW, this is my point exactly. The twirly finger is used for a variety of reasons to indicate that you merely want to turn around. However, it's important to clearly communicate to the team when dive limits have been reached. This is why we have reserved a signal for this that cannot be misunderstood.

I don't associate thumb with emergency per se, I would appreciate getting thumb-thumb-thumb to make it really clear you are in deep trouble to be honest. Thumb is just a higher gear that strips out all the extras off from exit and makes me more alert. Usually, with regular buddy we'd turn and a thumb-explanation would come very soon (eg I am cold/drysuit leaky). In most cases, could have as well twirled and explained but the thumb just established right away that no cameras are pulled out, no detouring, let's just head for the first stop and get out. I think the recent JB accident was a good example from buddy's perspective why it's good to know why to just obey the thumb in some cases.

I do not like having million different signs but I do like to be in the know if unexpected decisions are made, so thumb and twirly work. If there really was an emergency with thumb we get going with the right attitude right away.

The times that I have thumbed the dive, I have always given the thumb, then some explanation with another hand signal on why, just so my buddy knows the reason.

I would like to propose another scenario, along the same lines as the OP, but slightly different.

Lets say you are diving the distance tunnel in Orange Grove, and have an issue. On exiting back to the gold line, the double arrows point towards Challenge, but that line is not traveled near as much as the line to Olsen in the original scenario. Also, there is no alternative exit point like pot hole. Which way would you go?

I have done this dive a few times, but I will hold off on what we did in our pre-dive planning to cover this issue until other people throw out their ideas.

in a well-traveled place like peacock, i'm off to the closest exit in an emergency (after confirmation with my buddy).

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Originally Posted by deepdiverbob

Lets say you are diving the distance tunnel in Orange Grove, and have an issue. On exiting back to the gold line, the double arrows point towards Challenge, but that line is not traveled near as much as the line to Olsen in the original scenario. Also, there is no alternative exit point like pot hole. Which way would you go?

I have done this dive a few times, but I will hold off on what we did in our pre-dive planning to cover this issue until other people throw out their ideas.

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In the case of the distance tunnel at OG, where if I recall, the jump is at about 900-950' with a total of about 1780' between OG and Challenge, there are a few things I'd consider.

1. Most of the flow (little as it is) is from distance tunnel to OG with not much flow between the distance tunnel and challenge,
2. the flow is out toward OG from the distance tunnel,
3. OG is the direction we came from so the line is verified,
4. the tunnel from the distance tunnel jump to OG is more frequently traveled, increasing the potential to encounter another team and their resources,
5. the tunnel in that direction is fairly large with no significantly low spots and basically no sharp bends to negotiate so it is a very direct and easy exit, and
6. getting out at Challenge would be really interesting.


So, I'd exit to the OG side as the line would be verified, it is probably faster, has more likely hood of bringing you into contact with another team and the differences in distances are minor and offset by the other factors.

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Originally Posted by BabyDuck

in a well-traveled place like peacock, i'm off to the closest exit in an emergency (after confirmation with my buddy).

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Does this mean we'd have a discussion at the distance tunnel jump? :D

3. OG is the direction we came from so the line is verified

Enough for me.