If you ever get the chance to go cave tubing you should give it a try. This is the first time I've seen it. I'm not sure you'd get away with it in the UK or North America for safety/legal reasons. Basically you get an inflated tractor inner tube, a waterproof head lamp, and you're off into the cave. Not a life jacket in sight. The first part of the cave has a rope on which you pull yourself, after that you paddle...... Not sure how deep the water is, didn't really want to know. All reservations aside, once you get inside the cave it is great fun. It is pitch black, but the head lamps are fine, there are other people around (and your guide) , and it is pretty easy going - no crawling through tight spaces. Great fun, something quite different. The walk into the cave takes in some great scenery, as shown in the attached photos. A trip I'd recommend to anyone.