Preparing For A Total Silt Out

[GLENFWB]

Okay, it is the coldest night of year here in NW Florida. I am sitting by a fire and doing some maintenance of my dive gear. Now, let me start by saying I am only cavern certified. I am trying to prepare my gear so I can begin my first cave class.

I dive with some good cave divers, who are nice enough to play in the caverns with me. I have tried to pick their brains on this subject....I would like to know what others think. Having completed my cavern class with a great instructor, Gregg Stanton (Wakulla Dive Center) we of course practiced lost line drills, and following the line in the dark, etc.

But, when doing these drills, there is always the knowledge that there is a competent instructor nearby who is watching. I was very anxious to successfully complete the drill, and to learn a skill that could potentially save my life one day. But, there was not the sense of, if I don't find this line I might die.

Now to the question....Apart from the drills we do in class, how have you practiced, or prepared for being in a total silt out situation? Could some of you share how you handled your first silt out? Did you find that your training was adequate when you were confronted with the REAL thing?

There is so much we can simulate in training, loosing our mask, running out of air, and many other things....but, I am apprehensive about what can really be done to prepare for a complete silt out where you have to stay on the line...or else.

I would appreciate advice, suggestions, or insight from some of you who have "been there, done that."

 

[cave heaven]

Hi,

both as cavern students before and cave instructors now, we believe the only way you will know is if your instructor is able to put you in a challenging enough for you situation to answer your question. Actual cave diving is the most amazing passion there is, yet the potential downside is often unforgiving.
Learn basic skills unremittingly, listen to others more experienced than you - but, above all, listen to yourself. As a future cave diver you will witness a respect for your diving partners, yet need to decide carefully who they are, since you will also learn that trusting you buddies may be fatal.
This is the best diving you can do (sorry, we are opiniated), but leave your ego at home when you decide who to train with. You will become a better and safer diver.

 

[SuPrBuGmAn]

Glen,

My first total siltout was in a bit of a restrictive passage. I had to let go of the line to turn my fatass around due to the way the cave was configured. Due to its small size(basically a ceiling above me, my belly not far from the silt on the bottom, and walls within inches of either side of me) a quick sweep of my hand had the line back where it was supposed to be.

Since then, I've been in a few caves that have great visibility going in, but little to no visibility on the exit(expectedly). It wasn't a suprise or anything, so I guess that came to some advantage to us and we were progressively penetrating slower over a set of dives in order to learn the cave and memorize where the line placements were. Getting back on the line, not seeing where anything was was easy since we could feel where the line was and backtrack in memory whats next, and whats next, and know where in the cave we were.

There's something to be said for progressive penetration and getting to know the cave well, especially in conditions where a total siltout is possible(or especially likely).




I think the most heightened my senses have ever been were when I was diving in a very large cave, where the line shot from one side of the cave to the other. Despite have decent visibility, at several points I couldn't see walls, ceilings, floors, nothing. Only a void with a line shooting into nothingness. I was definately OK'ing the line then

 

[GLENFWB]

Thanks Mat. I can see where progressively penetrating has advantages. I have done over 12 dives in Jackson Blue cavern. I can sit here, and in my mind I can see where I like to place my line...and then the placement of the gold line all the way to the back. But, a silt out in an unfamiliar area would be an anxious situation. Thanks for the input.

Glen,

My first total siltout was in a bit of a restrictive passage. I had to let go of the line to turn my fatass around due to the way the cave was configured. Due to its small size(basically a ceiling above me, my belly not far from the silt on the bottom, and walls within inches of either side of me) a quick sweep of my hand had the line back where it was supposed to be.

Since then, I've been in a few caves that have great visibility going in, but little to no visibility on the exit(expectedly). It wasn't a suprise or anything, so I guess that came to some advantage to us and we were progressively penetrating slower over a set of dives in order to learn the cave and memorize where the line placements were. Getting back on the line, not seeing where anything was was easy since we could feel where the line was and backtrack in memory whats next, and whats next, and know where in the cave we were.

There's something to be said for progressive penetration and getting to know the cave well, especially in conditions where a total siltout is possible(or especially likely).




I think the most heightened my senses have ever been were when I was diving in a very large cave, where the line shot from one side of the cave to the other. Despite have decent visibility, at several points I couldn't see walls, ceilings, floors, nothing. Only a void with a line shooting into nothingness. I was definately OK'ing the line then

 

[Meng_Tze]

To me there are two aspects to a silt out. The physical and the mental. The physical are: the passage, the type of silt, the flow, the line, depth, gas, time etc..... These can all be trained and planned to a certain extend. Managing these can keep you alive if it all comes together. The mental aspect is the glue that either makes things come together, fall apart or just fades things out.

You sometimes read that people are found in systems with notes written to dear ones, gas in tanks etc, etc. To me that is somewhat strange and indicates they may have 'given up' or could not figure out how to get out of that situation.

All cave divers will at some point find themselves in a silt out, maybe even lost from a line as well. The key is to stop and prevent yourself from panicking. Think things through, come up with a plan and execute. Keep going forward. The moment you resign yourself to 'not making it out' you will die in that system. There is always an off chance of making it out, the human body and mind are far more powerful than we give it daily thought.

Silt outs happen, how it affects your mental state is the key.....

 

[brockbr]

One thing I'd add is this... Silt-out's aren't instantaneous. What I mean by that is you can usually see them coming (usually by the actions of your team - Tight passage and #2 diver is already in a silt-out )

Depending on the size of the cave at the time, I'll usually be in 1 of 3 positions:
1) Tight passage, clay bottom? - OK'ing the line
2) Bigger passage or sand bottom - Within 3 kicks of the line
3) Big passage and/or large voids with the line on a wall - Up to 5 kicks away.

I personally got silted out by my buddy in a 3' - 3 1/2' high bedding plane with a clay bottom 4,100' back. We were on scooters (both diving rebreathers) and he hooked a cylinder off the ceiling and dug into the clay floor bouncing free .

Went from 100' of viz to no viz in about a second and a half. The only thing I had time to do was grab the line. I sat there, in the absolute zero viz "tan-ness", and thought to myself "Wow - That was stupid - Now look at me - Do I *REALLY* need to be here?"

Everything worked out fine. Following the line I eventually made it out of the majority of the cloud (back to 3-5' of viz), which dissipated across the width of the bedding plane.

Can you "prepare" for that? Knowledge is key - Know everything you can possible know about the situation - Know what you're doing, and be mentally ready for it. In my case, know how to operate and fly your rebreather on the HUD blind (could still see vague colored lights), know how to stow the scooter blind, know generally where the line should go (this one stayed on the ceiling), know how much run-time you have left (I had over 4 hours left - Enough to get on the ceiling, take a nap, and let it clear back to 100' viz ). Know how to bailout blind, etc, etc.

One other tip - Laugh. You might be surprised, but if you feel yourself getting stressed, figure out a way to see humor in it. There have been studies on the subject and you can actually change your response to some of these situations simple by how you view them. Viewed as "oh crap, I'm going to die", and you very well may. Viewed as "shoot - THAT was stupid" and work out the problems - You stand a better chance.

 

[GLENFWB]

Thanks for the great insight. I just finished reading Sheck Exley's book, "Caverns Measureless To Man". You have stated principles that helped him survive in the early days of cave diving. I really appreciate you input on this.

To me there are two aspects to a silt out. The physical and the mental. The physical are: the passage, the type of silt, the flow, the line, depth, gas, time etc..... These can all be trained and planned to a certain extend. Managing these can keep you alive if it all comes together. The mental aspect is the glue that either makes things come together, fall apart or just fades things out.

You sometimes read that people are found in systems with notes written to dear ones, gas in tanks etc, etc. To me that is somewhat strange and indicates they may have 'given up' or could not figure out how to get out of that situation.

All cave divers will at some point find themselves in a silt out, maybe even lost from a line as well. The key is to stop and prevent yourself from panicking. Think things through, come up with a plan and execute. Keep going forward. The moment you resign yourself to 'not making it out' you will die in that system. There is always an off chance of making it out, the human body and mind are far more powerful than we give it daily thought.

Silt outs happen, how it affects your mental state is the key.....

 

[GLENFWB]

You guys are giving me some good stuff to think about! It seems that most of you are saying that there are some physical aspects to silt out, line awareness etc., but that the greatest part of dealing with a silt out is the mental battle. This is GREAT information...THANKS

One thing I'd add is this... Silt-out's aren't instantaneous. What I mean by that is you can usually see them coming (usually by the actions of your team - Tight passage and #2 diver is already in a silt-out )

Depending on the size of the cave at the time, I'll usually be in 1 of 3 positions:
1) Tight passage, clay bottom? - OK'ing the line
2) Bigger passage or sand bottom - Within 3 kicks of the line
3) Big passage and/or large voids with the line on a wall - Up to 5 kicks away.

I personally got silted out by my buddy in a 3' - 3 1/2' high bedding plane with a clay bottom 4,100' back. We were on scooters (both diving rebreathers) and he hooked a cylinder off the ceiling and dug into the clay floor bouncing free .

Went from 100' of viz to no viz in about a second and a half. The only thing I had time to do was grab the line. I sat there, in the absolute zero viz "tan-ness", and thought to myself "Wow - That was stupid - Now look at me - Do I *REALLY* need to be here?"

Everything worked out fine. Following the line I eventually made it out of the majority of the cloud (back to 3-5' of viz), which dissipated across the width of the bedding plane.

Can you "prepare" for that? Knowledge is key - Know everything you can possible know about the situation - Know what you're doing, and be mentally ready for it. In my case, know how to operate and fly your rebreather on the HUD blind (could still see vague colored lights), know how to stow the scooter blind, know generally where the line should go (this one stayed on the ceiling), know how much run-time you have left (I had over 4 hours left - Enough to get on the ceiling, take a nap, and let it clear back to 100' viz ). Know how to bailout blind, etc, etc.

One other tip - Laugh. You might be surprised, but if you feel yourself getting stressed, figure out a way to see humor in it. There have been studies on the subject and you can actually change your response to some of these situations simple by how you view them. Viewed as "oh crap, I'm going to die", and you very well may. Viewed as "shoot - THAT was stupid" and work out the problems - You stand a better chance.

 

[Meng_Tze]

But you will never know how you feel/react until you get there. Confidence in your own abilities and proper training to manage the dive, etc are the foundation.... the rest is between the ears.

 

[Dive-aholic]

Glen, a lot of great advice here. My first silt out was shortly after I received my Intro training. I was checking out a low cavern that pinched down quite a bit and ended up having to turn around about 50' in. I couldn't even see my gauges. As I turned around I didn't reel in fast enough and ended up having quite a bit of slack in the line, enough that I questioned whether I was turning the reel the right way and had to turn back to see it and verify I was. The key thing that kept me from stressing out in there was that I knew I was only 20' deep, had a set of doubles on my back with over 2000 psi in them, and my wife was about 50' away from me waiting. I knew I had plenty of air to stay there for a few hours. I went over a hundred cave dives after that without getting into a silt out. Since then every silt out I've been in has been expected. They have been in small sidemount passages where silt is inevitable and expected during the return trip. Basically what I'm trying to say is even though we train for silt outs, they're not all that common. But when they do happen, just keep your cool. Hold onto the line and trust it. That's what it's there for. I've been through several silt outs or simulated silt outs since I started cave diving. I've had to follow lines out several times, even lines with very few line arrows. If you want to simulate silt outs, head out into the gulf at the St. Andrews jetties and run some line out towards the bay. The visibility gets really crappy out that way. Then follow the line back and forth. Even though you know you have the surface above you, you have very little, if any, visibility here. Or if you want to avoid the salt, come over and dive with me. We'll run some drills and get you feeling more comfortable and prepared for it.