Duke Kahanamoku (August 24, 1890 – January 22, 1968), was a Hawaiian athlete who is called the inventor of modern surfing. He was also on the United States Olympic team as a swimmer, and won several silver and gold medals.
Contrary to some misinformation on the internet, Duke is not known as the Big Kahuna. He himself rejected that term, because he knew its meaning. The Big Kahuna is a character in the Gidget story, which is based on a portrayal of Tube Steak Tracy, a famous surfer of the '40s & '50s in Malibu.