I remember skipping stones as a kid, typically getting about 3-5 skips and occasionally reaching 10 or so. Kurt Steiner was participating in a stone-skipping competition and had the toss of a lifetime. The judges determined it was a total of 34 skips (and how they came up with that number I’ll never know—it looks like the stone is sliding across the water). Subsequent analysis of the slow-motion video showed the actual number of skips to be 40, which put Steiner in the Guinness Book of World Records. The site includes videos of the toss, at both regular speed and slow motion.