Our local mudhole is right next door to a dock where a city-run water taxi comes in. Divers are prohibited from getting within 150 feet of the dock, and there used to be a nice rope line underwater that delimited that forbidden space. It was marked with big yellow buoys on the surface. But a couple of years ago, when they rebuilt the dock, the line got caught by a barge and dragged all over, and some of the buoys were lost. By this spring, there was only one left, and the line was in crazy zig-zags on the sea floor.
So a local dive club, which has put a lot of work into installing and maintaining this line, extracted some money from the city for repairs, and I showed up yesterday for a work party dive. The job my buddy and I were given was to resurvey a temporary line that had been installed the week before, and continue it into the shallows, until it connected with the boulders that make up the sea wall there. We had a 150 foot section of polypropylene rope to use as a sort of compass (in the draft sense), and a big plastic spool of smaller polypro line to put in as temporary boundary.
The plan was to drop and tie the polypro rope off to a piling stub at the dock, and then run it to the temporary boundary. We were then going to shoot a bag to mark the shallow end of that line, and swim the polypro in a big arc, while laying the smaller line. But what we discovered, when we got underwater, was that we were dealing with a terrible siltout -- of Mother Nature's doing! Visibility was (and although I am given to hyperbole, I am not guilty of that here) about 18 inches at best. Even using lights, the only way my buddy and I could stay together was for one of us to hold the line, and the other to okay it; in addition, because it was slack line, we had to disentangle one another and ourselves at regular intervals. Once we found the temporary boundary, we had to lay line going upslope, so there we were, putting in tie-offs in zero viz (my cave class didn't really teach me to do that!)
At any rate, about a half hour into this whole thing, I started laughing. I felt as though I was back in Cave 1, doing blackout drills, only with much worse equipment and supplies. (In retrospect, we could have made the whole thing easier with some cave equipment, I think -- a knotted reel would have been handy -- but I had to work with what the organizers supplied.)
We got our entire part of the project finished, despite the horrendous viz, and I credit my cave training a lot for it having been possible. You just never know where those skills are going to come in handy!
So a local dive club, which has put a lot of work into installing and maintaining this line, extracted some money from the city for repairs, and I showed up yesterday for a work party dive. The job my buddy and I were given was to resurvey a temporary line that had been installed the week before, and continue it into the shallows, until it connected with the boulders that make up the sea wall there. We had a 150 foot section of polypropylene rope to use as a sort of compass (in the draft sense), and a big plastic spool of smaller polypro line to put in as temporary boundary.
The plan was to drop and tie the polypro rope off to a piling stub at the dock, and then run it to the temporary boundary. We were then going to shoot a bag to mark the shallow end of that line, and swim the polypro in a big arc, while laying the smaller line. But what we discovered, when we got underwater, was that we were dealing with a terrible siltout -- of Mother Nature's doing! Visibility was (and although I am given to hyperbole, I am not guilty of that here) about 18 inches at best. Even using lights, the only way my buddy and I could stay together was for one of us to hold the line, and the other to okay it; in addition, because it was slack line, we had to disentangle one another and ourselves at regular intervals. Once we found the temporary boundary, we had to lay line going upslope, so there we were, putting in tie-offs in zero viz (my cave class didn't really teach me to do that!)
At any rate, about a half hour into this whole thing, I started laughing. I felt as though I was back in Cave 1, doing blackout drills, only with much worse equipment and supplies. (In retrospect, we could have made the whole thing easier with some cave equipment, I think -- a knotted reel would have been handy -- but I had to work with what the organizers supplied.)
We got our entire part of the project finished, despite the horrendous viz, and I credit my cave training a lot for it having been possible. You just never know where those skills are going to come in handy!
