Challenge question III

BTW Cindy, Great idea for a thread. We may have to make a new forum for this!!!!!

High flow cave with a mixture of medium to large passages

2 member dive team on scooters and backmounts.

Gas on diver 1 just before incident 2500 psi (about 200 psi above thirds)

Diver 2 gas remaining unknown

Both divers diving 34% nitrox

Depth 100-110 feet. Time into dive, about 25 minutes.

Vis at start of incident 60+ feet

The two divers scootered into the cave with diver 1 leading. The mainline was still going at app 2500’ but the cave was getting very small, too small for scooters with the flow dropping rapidly.. The passage was about 10 feet wide but getting down to less then 4 feet tall quickly and diver 1 signaled to turn around. As diver 1 lost visual contact with the line during the turn around something happened that caused a significant amount of silt to develop and in a matter of a few seconds visibilty dropped to zero, a total silt out..
Diver 1 had let off the trigger to turn in the small place and was facing towards the exit, as far as he knew, when the total silt out occurred. Diver 1 had no idea what had caused the silt out and suspected some sort of natural event due to the amount of silt. Diver 1 slowly sank to the floor of the cave which was a combination of sand/silt/rock with no way to tie anything off. Diver 1 had last seen the line about four feet to his left near the wall before executing the turn around by turning to his right away from the wall and the line.
After settling to the bottom, Diver 1 could not hear his buddy’s scooter, could not see his light and could not even read his own gages as the vis was zero, nada, zilch. He remembered checking his gas supply at about 2500 psi a minute before the incident.
Diver 2 had been in a larger space and had made his turn under power. Diver 1 suspected Diver 2 was not any closer then 30-40 feet and possibly further away. The only way out was the way they had come. As Diver 1 went through his mental checks to formulate a plan, about a minute passed and the visibility did not improve one iota.

What would you do?

Scary stuff. I won't ask why the team was diving thirds on scooters - that's another story. But it's what makes this scary.

Given the small size of the passage, I'd give priority to relocating the line. In a 4 ft passage one should be able to find it pretty quickly.

It'd be tempting to swim back towards the exit to find better viz but if it was some event like a rock fall you could just end up having to search for the line in an even bigger passage.

Once I'd located the line, I'd mark which way I think is out and start exiting with the scooter clipped off to me like a stage, hoping for better viz and to locate my teammate.

As Diver 1, I'd first try to stretch my arms out and see if I could snag the line, leaving one hand and scooter at the "lost" point as a pivot. Do not lose this reference "pivot" point and get more lost. If the line's only 4 ft away, then it's within reach. If I could not reach it, I'd deploy my safety spool using a backup light as an anchor in the floor. Once the line was found, I'd mark the direction I attempted to go and start my exit. Since diver 2 should be downstream, I should feel a tieoff if he was doing a lost buddy search or bump into him. If I felt neither, I'd bang on tank and see if I got a reply. If not, I'd try going downstream a little further for clearer passage and re-evaluate if he could have gotten off the line too. If he hasn't replied to a tank bang and you can't see his light and you can't hear his breathing or his scooter running and you didn't run into him or a tieoff on the line, it would be a hard call to leave assuming he ditched you. It would be best to do a lost diver search just in case you assumed wrong.

As Diver 2, I'd wait for him a few minutes on the line for him to show. Then execute lost diver drill if he hasn't come.

In my training, we were told to always turn in the direction of the line. So you'd always be facing it. If you turn opposite the line, then you risk entanglement. Not even a bad idea to always get close to the line just before turning also, esp in small cave where silt is probable.

Sounds like the Little River incident from a couple years back...

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Originally Posted by mmcauliffe

Sounds like the Little River incident from a couple years back...

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Yes, it does.

Like I said in "Challange Q. II". Look for each other for 5 minutes, or so, then exit. In LR both divers found the line, but one waited too long to begin an exit.

And thirds on a scooter is a bad plan at best.

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Originally Posted by FW

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Originally Posted by mmcauliffe

Sounds like the Little River incident from a couple years back...

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Like I said in "Challange Q. II". Look for each other for 5 minutes, or so, then exit.

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I disagree (sorry!!). In this one I'd get the hell out quickly. in the other one I'd search for a LOOOONG time. I think they're very different scenarios.

could you not plant something in the floor, a backup light maybe, and tie off to that? leave the scooter jammed into the bottom? although you may need it to exit.... then do the lost line drill. The passage was small, getting smaller going in, so once the mainline is found, getting out is a matter of feeling (arms extended is about 5 feet or more) if it's getting smaller or larger and thus knowing if you are proceeding right or wrong direction.

Buddy was behind, but maybe now ahead, who can tell. if both divers do lost line drill they could pass one another and never know.

By leaving a line arrow to indicate which direction you went (and if buddy did same), then you'd either run into buddies line arrow or he into yours. At some point I assume it clears and then you can figure out if enough gas/time to do lost buddy search assuming you didn't run into buddy, or his arrow, already.

-skip

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Originally Posted by skip

By leaving a line arrow to indicate which direction you went (and if buddy did same), then you'd either run into buddies line arrow or he into yours. At some point I assume it clears and then you can figure out if enough gas/time to do lost buddy search assuming you didn't run into buddy, or his arrow, already.

-skip

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The problem with arrows is they should always point the way out, not the direction someone last went. It is also possible that they are just there as personal markers. The only thing they might tell you is that the buddy did find the line. Notes are probably better.

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Originally Posted by FW

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Originally Posted by skip

By leaving a line arrow to indicate which direction you went (and if buddy did same), then you'd either run into buddies line arrow or he into yours. At some point I assume it clears and then you can figure out if enough gas/time to do lost buddy search assuming you didn't run into buddy, or his arrow, already.

-skip

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The problem with arrows is they should always point the way out, not the direction someone last went. It is also possible that they are just there as personal markers. The only thing they might tell you is that the buddy did find the line. Notes are probably better.

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I agree Forrest. We've seen this in the past where an incorrectly placed navigational marker actually facilitated the fatality. In a silt out situation and I am on the line,I use feel of a line arrow to determine direction of travel,plus if the silt out is bad enough you couldn't see initials to indicate if they belonged to a buddy. Some people will say they put special marks on their line arrow ie a notch,but in a stressful situtation most people will probably not stop long enough to grope the line arrow to find if is a "permenant" or "temporary" line arrow.

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Originally Posted by aainslie

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Originally Posted by FW

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Originally Posted by mmcauliffe

Sounds like the Little River incident from a couple years back...

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Like I said in "Challenge Q. II". Look for each other for 5 minutes, or so, then exit.

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I disagree (sorry!!). In this one I'd get the hell out quickly. in the other one I'd search for a LOOOONG time. I think they're very different scenarios.

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You are right, they are different. In CQ2 you would have a lot more gas to search, but that won't help if your buddy has already left. I still think in both cases, look first near the point of separation, then look along the line toward the exit.

If you get out and don't find your buddy then you can decide if you need more gas/help to search, or in the case of CQ2 you should have plenty to go back and look again. No point in searching for someone who had managed to find their way out.

If you always dive with the same buddy, you should know if they would stay, or leave. If you dive with a lot of different people, it would be good to discuss what to do in case of separation before the dive.

Good answers!!!!

A little more info and what happened in the next phase.

It was impossible to turn into the line as it was too close to the wall.

After using the scooter and leash as a pivot, the line could not be reached.
Diver one decided to tie off a reel to the scooter and stretch a little further and immediately found the line and retrieved the scooter, (clipping it off like a stage)

Diver 1 started a LD search from that point and found Diver 2 coming back towards him along the line after about 50 feet. Vis had improved to about 4-6" Diver 1 knew they were approaching a larger room with big sand piles but still did not know what had happened.

After touch contact signals to confirm both were ok and to head out, Diver 2 immediately took off, leaving diver 1 to follow along the line with less then 6" of vis.
After about another 50-100 feet, diver 1 heard Diver 2's scooter ahead of him, vis had increased to about 6". Diver 1 continued another 50 feet or so and the scooter sounded close but Diver 1 still had no vis and was wondering WTF?

Now what do you do?

Check to make sure you didn't miss a Y or jump. You buddy may be off on another line. You might backtrack and if you find that is the problem I would put a line in with a arrow to show the way out. He should figure out he is on the wrong line and go back. If you have the line in for him at least he may may it out. If you are sure you are in the the right tunnel keep going down the line and exit. If he turned his scooter on he must have good vis or a death wish.... EIther way by the time you find the jump and chase him it will be too late for both of you. :!:

"Diver 2 immediately took off, leaving diver 1 to follow along the line with less then 6" of vis.
After about another 50-100 feet, diver 1 heard Diver 2's scooter ahead of him, vis had increased to about 6". Diver 1 continued another 50 feet or so and the scooter sounded close but Diver 1 still had no vis and was wondering WTF?

Now what do you do?"

stop, breathe, think.

sounds like maybe diver 2 is stirring up the silt and diver 1 is eating dust, er, silt. maybe there's been a cave-in, so that diver 2 is digging through? as long as you are on the line, making progress, best to just keep going. I'd hope that diver 2 would stop for some touch contact, an ok signal would be nice about now, or a line arrow indicating you are on the way out, but I'm not a scooter diver and from this challenge question I'm not so sure I want to be one!

I never thought of a missed jump or a T, as cindy did....not sure what that has to do with the continued poor viz, but dang, this is not a good situation!

-skip

You keep heading out. You're now moving slower in low-no vis and don't know how long it will take to get out, but you know it will be longer than coming in.

Assumes of course that A. you're on the right line, and B. that you're actually headed out. You don't really have time to deeply ponder the why's, you're pointed in the right direction as far as you know and you seem to be heading toward the sound of your buddy's scooter. Maybe he tried gunning it and ran into a mud bank or something. If he's off the line you would probably have to run into him to find him.

I'm ambivalent about placing an arrow, could help your buddy, could hurt. But, thinking short term only, if you could identify it (by feel since you might not be able to read written initials) as yours and you found some reason to think you needed to turn around to get out, you would know that you placed it when you encountered it again.

Not especialy familiar with scooter practices yet, but for the moment there it would seem that you would just need to keep swimming until you get enough vis/passage size to fire up the scooter. Or you get low enough on gas swimming that you have nothing to lose by trying to scooter out in less than ideal vis.

There is no good way to continue this thread except to tell what happened.

D1 suspected D2 was above him as he intermittently started and stopped the scooter to attract attention D1 tied off to the line with an arrow and followed the profile of the cave up towards the ceiling. After about 20 feet the vis cleared and D1 found D2 in a pocket of fairly clear water at the ceiling of the room. D2 wanted to wait for the vis to clear and D1 allowed a few minutes to pass. D1, still unaware of what had caused the silt out ‘encouraged’ D2 to go back to the line and head out. They were still 2200 feet or so back at 100 foot depth and D1 wanted to get going before too much gas was used as he thought he still had to contend with the cause of the silt out.

Once at the line, D2 again took off swimming with no touch contact. Vis had increased to 2-3 feet and D1 tried to keep his fins in sight as he OK’ed the line. There was several hundred feet of smaller passage before the next large room. Flow had picked up and vis was very slowly returning when D2 again shot off the line towards the ceiling. D1 tied off to the line and followed up. This big room had a much larger clear area at the top of a sand hill. D2 wanted to wait for the vis to clear up some more, but D1 was at 2000 psi and D2 was much less. D1 insisted on getting back to the line and heading out as the vis was sufficient to make good time swimming with line contact.

D2 swam off immediately down the line and after a minute or so D1 heard his scooter startup and vis went back to 6 inches or less. D1 continued performing a line drill for 300 + feet before the vis increased enough for a decent swim pace. He could hear D2’s scooter in the distance and eventually found him waiting in a spot where the vis was 20 feet. At this point the cave was large enough and vis was good enough for both divers to head out at maximum speed on the scooters. After several hundred feet vis returned to almost normal.

Deco obligation was met and after some spirited discussion in the basin the cause of the event unfolded.

D2’s scooter stuck on several times resulting in a Massive silt out. D2 had what is a common urge, get out of the silt to clear water. This can become a strong urge after a period of time in zero visibility. D2 was aware of what caused the issue but never communicated it to D1 inside the cave. He was content to find clear water to hang out in and wait for the silt to clear, but would not take the time to run a reel from the line to the clear spot.
Waiting for the silt to clear can be a good strategy in a high flow cave, but it has to balanced with the amount of air remaining and the exit time. D2 never had very good air consumption and his SAC rate would skyrocket to dangerous levels under stress or workload. In this case, he waited until his gas was dangerously low for the situation.
D2 was also reluctant to maintain touch contact on the exit and would swim as quickly as possible. Without maintaining buddy contact and with poor gas management, D2 was fortunate that no other incidents occurred on the exit. A loss of either scooter, a light, entanglement or any significant delay during the remainder of the exit would have forced D1 into sharing air with D2. At D2’s increased consumption rate under stress a significant delay could have been deadly.

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Originally Posted by Jay

Once at the line, D2 again took off swimming with no touch contact.

D2 swam off immediately down the line and after a minute or so D1 heard his scooter startup and vis went back to 6 inches or less.

D2 was aware of what caused the issue but never communicated it to D1 inside the cave. He was content to find clear water to hang out in and wait for the silt to clear, but would not take the time to run a reel from the line to the clear spot.

D2 was also reluctant to maintain touch contact on the exit and would swim as quickly as possible. Without maintaining buddy contact and with poor gas management, D2 was fortunate that no other incidents occurred on the exit.

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at first i thought all these threads were about challenge sink at peacock... :oops: wonderful idea for a series, cindy. thanks to everyone for their scenarios!

i have no experience at all with scooters except when my buds who have one allow me to caress it...BUT -

i would never again dive with a buddy who left me purposefully in the #### without touch contact. anyone can have an accident and lose buoyancy or screw up their scootering or whatever and silt things up, but if you *leave* me in it once, it will be the last time. and this person found you and then left you several times!! and because i'm vindictive, i would tell the story to everyone & try to see that their pool of buddies mysteriously dried up...

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Originally Posted by BabyDuck

i would never again dive with a buddy who left me purposefully in the sh^t without touch contact. anyone can have an accident and lose buoyancy or screw up their scootering or whatever and silt things up, but if you *leave* me in it once, it will be the last time. and this person found you and then left you several times!! and because i'm vindictive, i would tell the story to everyone & try to see that their pool of buddies mysteriously dried up...

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I second this. I'd be pretty upset the first time D2 took off. The 2nd time would be the last time. As I read Jay's last post, I just kept wondering what D2 was doing. This is completely against what we're trained to do, yet D2 is doing it over and over again. No touch contact, leaving the line, scootering in low visilibility. D2 not only put himself in danger, but also D1. Not a good situation.

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Originally Posted by BabyDuck

at first i thought all these threads were about challenge sink at peacock... :oops: wonderful idea for a series, cindy. thanks to everyone for their scenarios!

i have no experience at all with scooters except when my buds who have one allow me to caress it...BUT -

i would never again dive with a buddy who left me purposefully in the sh^t without touch contact. anyone can have an accident and lose buoyancy or screw up their scootering or whatever and silt things up, but if you *leave* me in it once, it will be the last time. and this person found you and then left you several times!! and because i'm vindictive, i would tell the story to everyone & try to see that their pool of buddies mysteriously dried up...

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Er , who are you calling all dried up??? :o
And caressing scooters now are we? Hmmm...

Da Bean

P.S. Sorry , I couldn't resist. :-D
And hope you and Jamison are doing GREAT !!!!

As far as being left behind by a buddy , it hasn't happened to me yet. Nor have I left a buddy behind yet either. I only HOPE either doesn't happen.

gotta caress something...and i know you'd never leave me purposefully in the stank!

D1 attempted to educate D2 about their diving attitude. That was unsuccessful and unfortunate.

ooh, details, details!!