In the sport of surfing, the winner is the surfer who scores the most points by riding waves. A panel of judges scores a surfer's ride by analysing the degree of difficulty, level of innovation, and progressiveness of manoeuvres performed, and the amount of variety of manoeuvres performed on one ride. Each surfer's two highest scores in a time-limited heat are totalled for his/her final score to determine the winner.
To earn a high score, a combination of manoeuvres with flow and grace, and speed and power are necessary. In particular, progressive wave-riding and rides with a high degree of difficulty are likely to be scored highly.
Since the sport requires riding on waves in natural conditions, adapting to waves at the venue and the changing conditions of waves, and tactics against other competitors in order to catch good waves, are the keys to win a competition.
Surfing is said to have been invented by ancient Polynesians living in Hawaii and Tahiti around 400 AD. In the 20th century, the sport was introduced to mainland America and rapidly gained in popularity in California and other places.
Duke Kahanamoku from Hawaii, the gold medallist in the 100-meter freestyle in swimming at the Stockholm 1912 Olympic Games and the 1920 Antwerp Olympic Games, was a surfer who helped popularize surfing around the world.
The origin of surfing in Japan can be traced back to around 1960, when some US troops in Japan began surfing off the coast of Shonan and Chiba, and young boys imitated them using a self-made surfboards. In July 1966, 100 surfers competed in the 1st All Japan Surfing Championship. In 2015, the 50th anniversary year of the All Japan Surfing Championship, approximately 1,000 surfers survived the preliminaries and competed in the Championship.
- Tsurigasaki Beach Surfing Venue