Waterfall Rappel To bound down backward over the face of this 60 foot waterfall at first seemed unfathomable. But so far on this backpacking and leadership venture with Costa Rica Outward Bound, "no" had not been a word in our vocabulary. So my group of twelve high school students took the plunge. I volunteered to be one of the first to go, and what I remember best about the descent was the feel of heavy torrents of water pounding against my chest, and the squish of the aqueous moss beneath my toes. From the bottom, no triumph had ever felt so grand.