In what situation would you leave your buddy?

[TSandM]

I truly love Danny Riordan, who was my Cave 1 instructor. Danny constantly tried to hammer into us the importance of taking "snapshots" of the cave -- depth, time, gas, notable features -- so that we would be able to make the most intelligent calculation of gas remaining to do something like a search.

The problem with "I have 1800 psi, so I'm 600 psi from the exit" is that, in high flow cave, it massively overestimates the requirement for exit, and even in low flow cave, if you have followed the recommendations to swim in very slowly, and out much faster, you may be much closer to the exit than you think you are, if you go only by consumed gas.

If my buddy goes missing, I want to be able to determine what the maximum amount of gas I can spend to look for him actually IS, and I don't want to throw away 2 or 300 psi because I'm using gross guidelines instead of paying attention to what I am actually doing.

(What I really want is to improve my awareness until there is NO way that my buddy is missing long enough for him or her to get further than I can spot them!)

 

[Dive-aholic]

I read Marci's post to mean she'd search for 1/3 of her reserve or 1/3 of the 1200 psi. While we must save at least 2/3 of the gas supply for exit, 1/3 of that gas will be assumed to be used for exit leaving the remaining 1/3 in true "reserve."

3600/3 = 1200 psi usable or 2400 psi turn for simple thirds.

Typical lost buddy expendable gas = 1/3 of the 1200 psi reserve or 400 psi for search.

Search begins at 1800 psi and terminates at 1400 psi without having found her buddy. She missed him by 100 psi since your scenario had the buddy located at 500 psi when she would have turned at 400 psi.

She should be 600 psi from the exit with 1400 in her tanks.

Exits cave with 800 psi left. She lives. Buddy dies.

In any case, gas reserves often assume just one emergency will occur during the dive. Gas reserves assume a lost buddy will be located and the team will exit normally in a lost buddy situation. In an out of gas situation at max pen gas reserve rules assume that will be the only problem. Padding the dive for two emergencies doesn't hurt.

Still not enough. She finds him at 400 psi, they begin their exit. They get back to the original location where separation was noticed (600 psi from exit), buddy runs out of air. She has 1000 psi but needs 1200 psi (probably more because buddy is still freaked out from getting lost and still breathing more). Still dead.

She finds him at 300 psi, they begin their exit. Get back to original location, buddy runs out, she has 1200 psi. Just enough. But it's more likely that the buddy will not run out of air that fast (hopefully) and they'll have a little left over at exit. This isn't as likely with the 400 psi scenario. Even if the buddy doesn't run out at that point and there is an additional 200 psi available, I don't trust gauges that much. Recently I pressure tested 5 different gauges (SPGs, pressure checkers, and a digital SPG on a booster) and I got 5 different readings, ranging from 100 psi difference to 500 psi difference.

 

[Trace Malinowski]

I truly love Danny Riordan, who was my Cave 1 instructor. Danny constantly tried to hammer into us the importance of taking "snapshots" of the cave -- depth, time, gas, notable features -- so that we would be able to make the most intelligent calculation of gas remaining to do something like a search.

The problem with "I have 1800 psi, so I'm 600 psi from the exit" is that, in high flow cave, it massively overestimates the requirement for exit, and even in low flow cave, if you have followed the recommendations to swim in very slowly, and out much faster, you may be much closer to the exit than you think you are, if you go only by consumed gas.

If my buddy goes missing, I want to be able to determine what the maximum amount of gas I can spend to look for him actually IS, and I don't want to throw away 2 or 300 psi because I'm using gross guidelines instead of paying attention to what I am actually doing.

(What I really want is to improve my awareness until there is NO way that my buddy is missing long enough for him or her to get further than I can spot them!)

Lynne, I'm glad you mentioned this because there is something I wanted to share for those who dive with their loved ones.

I was taught and teach my students to do the same thing Danny Riordan taught you. But, having been through a lost buddy situation with my girlfriend in which training went right out the window, I now also draw upon the lessons of naval aviators in Laurence Gonzales' book, Deep Survival:

If you could see adrenaline, then you'd see a great green greasy river of it oozing off the beach at San Diego tonight. You'd see it flowing one hundred miles out toward the stern of the boat -- that's what the pilots call it, a boat, despite the fact that it displaces over 95,000 tons of water, has a minimum of six thousand people living on board at all times, and is as long as the Empire State Building is tall...

... I hear Yankovich through the headphones inside my cranial and turn back to the F-18 bearing down on us. He's speaking over the telephone handset. The pilot's quaking voice responds, "Three-one-four Hornet b-b-ball, three point two."

"Roger ball, wind twenty knots axial." He's at a quarter mile, a child in a glass bubble, alone in the night, with the dying yellow stars of deck lights below ...

Yankovich explained the most salient points: "You're at a quarter mile and someone asks you who your mother is: you don't know! That's how focused you are. Okay, call the ball. Now, it's a knife fight in a phone booth. And remember: full power in the wire. Now, your IQ roles back to that of an ape." It sounds as if he is being a smart ass (he is), but deep lessons are also there to be teased out like some obscure Talmudic script. Lessons about survival, what you need to know and what you don't need to know. About the surface of the brain and its deep recesses. About what you know that you don't know you know and about what you don't know that you'd better not think you know.

This last part, the part about what you don't know that you better not think you know is the part that will get you killed.

Do you want to get creative with your gas management when your brain begins to find your inner Neanderthal or do you want a solid rule - something that you will remember to save your life at least even if you are dying to save another - especially someone you love?

Having made several rescues in which I was emotionally detached, I can attest that it is possible to do an awful lot of thinking during the process. As an ER physician you know exactly what I mean. But, when it is someone you can't lose, maybe someone you can't live without, having the rules firmly embedded somewhere may save a life.

 

[Trace Malinowski]

Still not enough. She finds him at 400 psi, they begin their exit. They get back to the original location where separation was noticed (600 psi from exit), buddy runs out of air. She has 1000 psi but needs 1200 psi (probably more because buddy is still freaked out from getting lost and still breathing more). Still dead.

She finds him at 300 psi, they begin their exit. Get back to original location, buddy runs out, she has 1200 psi. Just enough. But it's more likely that the buddy will not run out of air that fast (hopefully) and they'll have a little left over at exit. This isn't as likely with the 400 psi scenario. Even if the buddy doesn't run out at that point and there is an additional 200 psi available, I don't trust gauges that much. Recently I pressure tested 5 different gauges (SPGs, pressure checkers, and a digital SPG on a booster) and I got 5 different readings, ranging from 100 psi difference to 500 psi difference.

That's why I said gas management rules assume one emergency will happen.

A lost buddy and an out of gas situation are two emergencies.

Yes, an out of gas may be a logical following occurrence if buddies were separated, but they could also create a silt-out if stressed during the gas-share. That delay could be counted as a third problem. You're right to quiz your students as to what they would do if this, then that, to ignite the thought process.

I just wanted to make it clear to the readers that gas rules assume only one thing will go wrong.

 

[Dive-aholic]

I truly love Danny Riordan, who was my Cave 1 instructor. Danny constantly tried to hammer into us the importance of taking "snapshots" of the cave -- depth, time, gas, notable features -- so that we would be able to make the most intelligent calculation of gas remaining to do something like a search.

The problem with "I have 1800 psi, so I'm 600 psi from the exit" is that, in high flow cave, it massively overestimates the requirement for exit, and even in low flow cave, if you have followed the recommendations to swim in very slowly, and out much faster, you may be much closer to the exit than you think you are, if you go only by consumed gas.

If my buddy goes missing, I want to be able to determine what the maximum amount of gas I can spend to look for him actually IS, and I don't want to throw away 2 or 300 psi because I'm using gross guidelines instead of paying attention to what I am actually doing.

(What I really want is to improve my awareness until there is NO way that my buddy is missing long enough for him or her to get further than I can spot them!)

That's why I specified low flow system.

And I teach my students differently. I stress to my students that they need to know the cave better on the way out than on the way in. It really doesn't matter what it looks like going in. You need to recognize the passage going out.

The line is only there to get you out of the cave when you lose visibility. It's not really there for any other reason. While I do reference it, I'm confident I can get out of the caves I frequent without guideline as long as I have visibility because I know them that well. While I don't think the exit should be delayed, I don't agree that it should be expedited. That is the time you really need to learn the cave.

That's why I said gas management rules assume one emergency will happen.

A lost buddy and an out of gas situation are two emergencies.

Yes, an out of gas may be a logical following occurrence if buddies were separated, but they could also create a silt-out if stressed during the gas-share. That delay could be counted as a third problem. You're right to quiz your students as to what they would do if this, then that, to ignite the thought process.

I just wanted to make it clear to the readers that gas rules assume only one thing will go wrong.

Tell that to the 2 guys at Jackson Blue that silted the passage out, got separated, and both ran out of gas 200-300' from the exit. The only thing that saved them was the pure, dumb luck of another diver on a scooter beginning his dive at the right moment.

 

[BabyDuck]

yes, rob, i meant 1/3 *of* the reserve, not the entire 1/3 that was reserved. and of course that's not a guarantee. *diving thirds is not a guarantee of getting two divers out from max pen!*

 

[cerich]

I truly love Danny Riordan, who was my Cave 1 instructor. Danny constantly tried to hammer into us the importance of taking "snapshots" of the cave -- depth, time, gas, notable features -- so that we would be able to make the most intelligent calculation of gas remaining to do something like a search.

The problem with "I have 1800 psi, so I'm 600 psi from the exit" is that, in high flow cave, it massively overestimates the requirement for exit, and even in low flow cave, if you have followed the recommendations to swim in very slowly, and out much faster, you may be much closer to the exit than you think you are, if you go only by consumed gas.

If my buddy goes missing, I want to be able to determine what the maximum amount of gas I can spend to look for him actually IS, and I don't want to throw away 2 or 300 psi because I'm using gross guidelines instead of paying attention to what I am actually doing.

(What I really want is to improve my awareness until there is NO way that my buddy is missing long enough for him or her to get further than I can spot them!)

flow as a factor aside, thirds is woefully inadequate under almost ever circumstance if shortly after you have someone on the long hose one or both divers don't get back in control. If you have a near panic diver (esp two) thirds is a disaster. Thats why i feel we need to practice donating (both sides of the skill) on a regular basis for a actual swim, preferably with some navigation, not just a brief part of s drills.

 

[Trace Malinowski]

Tell that to the 2 guys at Jackson Blue that silted the passage out, got separated, and both ran out of gas 200-300' from the exit. The only thing that saved them was the pure, dumb luck of another diver on a scooter beginning his dive at the right moment.

That's two things. Lost buddy + silt-out.

The gas management rule of reserving 1/3 of your gas for your buddy's exit also encompasses additional gas for the possibility of a delay on exit such as a lost buddy, or a silt-out, or a post failure, or anything else that might require either time or gas since time is gas and gas is time.

When two or more things happen, that reserve supply may not be enough.

In your example of the near-miss at JB, any cave student who has had to do land drills for a touch contact exit while the instructor timed the process remembers how long it took. In most cases, easily three or more times as long. Think about how long it took to do a lost buddy land drill. Now, take both of those drills into the water - longer yet. Now, they are no longer drills, but the real thing. The divers may be rusty and we need to add the stress of the possibility of drowning.

The gas reserve may allow them time to reunite after a search or it may allow them to exit through silt, but may not be enough to allow them to reunite AND exit through silt. Cave divers need to keep their equipment, mindset and skills tight because we can't allow ourselves to add any links to the accident chain. If something goes wrong, we need to pause and think while maintaining good trim, buoyancy and still use the correct propulsion once we do move. Our gas rules might barely get us out of an OOG at max pen, but not an OOG at max pen with the lights out or through silt, or when lost of the line.

One easy gas safety to add is to take out a 500 psi rock bottom and calculate thirds or sixths off the remaining supply. This also may not be enough. The farther you are from the exit, the more complicated your navigation home, the worse the visibility, the less help from outgoing flow, the less skilled and practiced the team, and the more links you create in the accident chain the more likely you will die.

 

[TSandM]

Another thing my Full Cave instructor did was make me do a lights-out exit from 38 minutes back in the cave-- halfway out, he grabbed the reg out of my mouth, so we finished the exit sharing gas. Then he sternly pointed out to me that it took us 44 minutes to exit, and that one can't afford that kind of delay if gas reserves are to be adequate. I had to do the whole thing over the next day (different passage, roughly same time) and that time, I got us out in about a minute less than we came in, but it took swimming much faster than I would naturally do in the dark, or sharing gas. It was a very good learning experience.

The JB incident is a perfect example of sliding down the incident pit. With good training, any single issue should be survivable, but when they begin to compound, the danger mounts exponentially.

 

[Trace Malinowski]

Another thing my Full Cave instructor did was make me do a lights-out exit from 38 minutes back in the cave-- halfway out, he grabbed the reg out of my mouth, so we finished the exit sharing gas. Then he sternly pointed out to me that it took us 44 minutes to exit, and that one can't afford that kind of delay if gas reserves are to be adequate. I had to do the whole thing over the next day (different passage, roughly same time) and that time, I got us out in about a minute less than we came in, but it took swimming much faster than I would naturally do in the dark, or sharing gas. It was a very good learning experience.

The JB incident is a perfect example of sliding down the incident pit. With good training, any single issue should be survivable, but when they begin to compound, the danger mounts exponentially.

Nice job!