Unexpected Siltouts

Have you ever been in a siltout with no warning whatsoever? The safety reel thread brought up this question. In answering, please elaborate on possible reasons.
I have been in some very tight places where siltouts were expected and you simply stay with the line. This has never been a problem, although the first time through a set of major restrictions in no vis is an eye opener.

Get off the main line or 'bubble trail' and have the ceiling start 'raining down ontop of you'.

Jumping to a tunnel that was zero flow and had been used for training 3min ago.

Having the camera man start fanning silt in your path....fire for effect?

Your point is a good one. Its an experience based skill. With the experience its just another day at the office....without your SAC rate can double and you see guys with the 'big eyes'. We've all been there at one point or another. Workup dives and progressive cave penetrations help.

The cameraman finning reminds me of a funny story. Sunday of the NSS convention this year a friend came down from Massachusetts (sp) for the conference and some diving. After the Duncan Price (CDG of Britain) sidemount workshop, we headed to Ginnie for a little swim. The first dive was a shakedown. The second was a little more unconventional. We took off for the only part of the cave that I'm very familiar with that guarantees no viz for at least 200 feet (in backmount). Since I was leading, I didn't tell the other two guys about how nice it was. (During the surface interval they were both ranting about how Ginnie is always clear as Gin)
Anyway, there are 3 T's in the line. The cave gets progressively smaller until your belly is a couple of inches from the clay and your back is on the ceiling. Then the depth changes come in. I could see at first, but I know they couldn't. We go to touch contact. The next hundred feet were slow, but very fun. I monitored their gas consumption by listening for the exhalations. One of the guys was diving a G250 Scubapro that made an odd hissing noise, which made it easy to differentiate between divers. I could hear their mind clearing more and more every few feet.
In all, the whole episode only lasted about 20 minutes, but that twenty minutes taught me how to judge one's perspective by the way they hiss (a skill that is all too often overlooked when you can see).
Anyway, the dude from Mass. had never really been in no viz for longer than two or three minutes, so he was stoked about the deal. When we got to the end of the circuit, I sent the second guy in front while I ducked a few inches out of viz in a side chute. The water cleared to near gin viz instantly. I turned my mask around backwards and came out of the redness with a big grin. I could hear them both howling with laughter (may have been narcosis).
The dude from Mass. sent me a book about a week later and said he would like a picture from that spot in that same perspective in return.
I haven't figured how to drag a Nikonos through that passage unscathed yet, but I'm working on it.

or some of the inbetween tunnels?

I did vaca ha last in mex and the halocline can be almost as bad as silt when stirred up really bad in smaller tunnels....but certainly not 20 min worth. Sometimes its just better to close your eyes and focus on the 'sixth sense'.

I definately see more with my eyes closed. That's a very nice way to put it.

At Mine Lamotte vis can be near zero near the entrance and some of the shallower areas. Further in the vis gets real nice. Had a new guy with us. We dove with him in our full cave class but not since. My wife led we put him in the number 2 spot and I took up the rear. He was not to happy with the vis I guess because he just sort of clawed his way along the bottom. I couldn't see anything except fresh swirls of mud in front of me. I had trouble establishing touch contact because of all his ups and downs. He also badly abused the line. He didn't turn the dive or have a clue where I was. I have seen others (not cave divers) just fall apart with the vis. This was the first time I seen it in a cave. I couldn't see but I had the line and it doesn't bother me. That is, when somebody isn't trying to break it.

Isn't mine lamotte where that train is? Can you give us some more input on the more interesting dives in that mine/system?

Time/depths/distances......things to see, places to go.

Since all of my dives are in places where classes train, shake down dives and the occasional openwater diver gets taken in by their cave buddies. I have come to expect a silt out on every dive.

The only occurance I ever had of an unexpected silt out was at Little River. After completing the dive we started to come up and to our suprise the top of the hole instead of being nice and clear was White. Like a milkshake.

All the rain had blown out the viz in the basin. We start to ascend from 20' by feeling our way up the rocks and sand. About 4 mins of this to keep our ascent slow and then we broke the surface laughing. Wow. that was cool and unexpected.

By the time we finished our surface deco the rain had stopped and within a minute conditions in the basin were clear.

A couple of places in the back of Telford and Peacock III were nice and silty but hardly unexpected.

maddiver once bubbled...
Isn't mine lamotte where that train is? Can you give us some more input on the more interesting dives in that mine/system?

Time/depths/distances......things to see, places to go.

Click to expand...

Hey Lance,

I feel like I spent all last year there. There's a bat cave, the Main road, the Equipment room, the carts and gear that the miners just dropped when the mine close, all sorts of stuff.

There is a circuit I like to do. In thru the Main Road to the Equipment Room, then out thru the Bat Cave.

Dives can be as long or as short as you want, and since you never break 70 ft in depth, they can go for hours.

When you get back from Scapa give me a shout, we'll see if we can get something going.

dive safe
Brock

Divesherpa once bubbled...
Have you ever been in a siltout with no warning whatsoever? The safety reel thread brought up this question. In answering, please elaborate on possible reasons.
I have been in some very tight places where siltouts were expected and you simply stay with the line. This has never been a problem, although the first time through a set of major restrictions in no vis is an eye opener.

Click to expand...

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boom:
Oh yeh sure have. I was doing a dive at Little River with a team of 4 cavers. Two cavers were new to the environment on their last cert dive. They were expecting something to happen on the way back out and it did! I was leading, I looked back for a second. The viz from the trip in was not that great Next thing I realized I was on the wrong side of the line to pass through a tunnel. Wedgee time! I tried to back out and tunk my tanks hit ceiling, move forward they hit again. I only had a few inches below me to drop and a fine clay silt lay below Only inches from my face was the line My light at this point was really whiting out the area. I just froze for a second to let things clear, adjusted my breathing and was getting ready to hand walk the ceiling from behind my head when I noticed that two of the cavers (students) just blew right past me and had no intent on staying there. They said later they thought that was part of their training. With my hands still out and not moving the 4th diver (instructor) simply pushed down on my tanks and moved me over then out we went. He said he was glad I didn't fight him. But than hey ain't that why we do the training? For the students and the instructor myself it was as always a good learning experience.