I'm not claustrophobic, but years ago I was reading an account of the first exploration of one of this country's longest caves (maybe Schoolhouse)? The lead spelunker would be working through a very small tube (rather like the video but head first, without knowing how the tunnel ended). The explorer would exhale, pull himself forward a few inches, then inhale. My palms were sweating just reading about it. When I first started dating my now wife, I knew she was claustrophobic but I didn't realize how badly; we were following a guide into a cave in Jamaica, with only the guide having a flashlight. We were just in about twenty feet and I turned to say something to Liz, but she was gone; I found her outside shaking and crying. She insisted I go back in and see the cave, which I did, and it was quite a Jamaican experience. You would walk along a tunnel in the darkness and every fifty feet or so an electric lantern would go on and a different little two minute show would be put on for you, like a Reggae band (of course each stop required tipping). I swore that the guide said we were going to see "the gerbil of the caves" which I was looking forward to seeing, but I must have misunderstood because it never was shown. At one point there was an ice cold underground stream a couple of foot deep which came out of solid rock, shot across the five foot wide tunnel, and disappeared into the opposite wall. There was a rock sort of like a stalagmite in the middle of the stream and the guide said if we climbed into the stream and held onto the rock, he'd turn off the flashlight and we'd feel the energy of the cave enter our bodies (maybe that had something to do with a gerbil... who knows). Well, I hopped in, wrapped my arms and legs around the rock, and stood there in the darkness, in the ice cold water, wondering if I lost my grip if they'd look for my body six months later in the ocean.