Stone skipping (or stone skimming) is the art of throwing a flat stone across water in such a way (usually Sidearm) that it bounces off the surface, preferably many times. The objective of the game is to see how many times a stone can bounce before sinking.
The North American Stone Skipping Association (NASSA), founded by Coleman-McGhee, in 1989 and is based in Driftwood, Texas, sanctioned world championships for four years from 1989 through 1992 in Wimberley, Texas. The next official NASSA World Championships is expected to be held at Platja d'en Ros beach in Cadaqués, Catalonia, Spain.
The world record for the number of skips Guinness Book of Records is 88 by Kurt "Mountain Man" Steiner, (b. 1965). The cast was achieved on September 6, 2013 at Red Bridge in the Allegheny National Forest, Pennsylvania. The previous record was 65 skips, by Max Steiner (no relation to K. Steiner), set at Riverfront Park, Franklin, Pennsylvania. Before him, the record was 51 skips, set by Russell Byars on July 19, 2007, skipping at the same location. Kurt Steiner also held the world record between 2002 and 2007 with a throw of 40 skips, achieved in competition at Franklin, PA. The US Stone Skipping champion 2018 at Franklin was Keisuke Hashimoto (Japan), at Mackinac Island Mich 2018 it was David Kolar.
A stone skipping championship of a different nature takes place every year in Easdale, Scotland, where relative distances count as opposed to number of skips, as tends to be the case outside the US. Since 1997, competitors from all over the world have taken part in the World Stone Skimming Championships in a disused quarry on Easdale Island using sea-worn Easdale slate of maximum 3" diameter. Each participant gets three throws and the stone must bounce/skip at least twice to count (ie 3 water touches minimum).The Guinness World Record for the furthest distance skimmed using natural stone stands at 121.8m established by Dougie Isaacs (Scotland). For a female it is 52.5m by Nina Luginbuhl (Switzerland). The records were made on 28th May 2018 at Abernant Lake, Llanwrtyd Wells, Wales.
|2002||Alastair Judkins||New Zealand|
|1997||Ian Sherriff||New Zealand|
|2008||Jillian Hunter||Northern Ireland|
An early explanation of the physics of stone-skipping was provided by Lazzaro Spallanzani in the 18th century.
The stone generates lift in the same manner as a flying disc, by pushing water down as it moves across the water at an angle. Surface tension has very little to do with it. The stone's rotation acts to stabilize it against the torque of lift being applied to the back.
Research undertaken by a team led by French physicist Lydéric Bocquet discovered that an angle of about 20° between the stone and the water's surface is optimal. Bocquet and his colleagues were surprised to discover that changes in speed and rotation did not change this fact, it just allow the stone to be in balance and to continue with a straight and uniform movement, due to gyroscopic effect. Work by Hewitt, Balmforth and McElwaine has shown that if the horizontal speed can be maintained skipping can continue indefinitely. Earlier research reported by Bocquet calculated that the world record of 38 rebounds set by Coleman-McGhee, unchallenged for many years, required a speed of 12 m/s (25 mph), with a rotation of 14 revolutions per second.