Duke Kahanamoku was born in Honolulu in 1890, three years before the overthrow of the Hawaiian Kingdom. Duke was his given name, inherited from his father, who was named for Prince Alfred, Duke of Edinburgh, and his family were of alii descent and served the Kamehameha royals as kahu. He left the Kamehameha Schools to help support his family and grew up on Waikiki Beach, surfing a 16 foot, 114 pound finless koa board he called his Papa Nui. In 1911 he swam the 100 yard freestyle in Honolulu Harbor in 55.4 seconds, 4.6 seconds under the record, and the Amateur Athletic Union refused to believe it, blaming alarm clocks and currents.

He answered with gold in the 100 meter freestyle at the 1912 Stockholm Olympics, gold again in 1920 in Antwerp, and silver in 1924 in Paris at age 34, behind Johnny Weissmuller and ahead of his brother Samuel. His flutter kick replaced the draggy scissors kick. Touring as a swimmer, he brought surfing to Southern California in 1912 and to Australia on December 24, 1914 at Freshwater Beach in Sydney. He later acted in Hollywood films including Mister Roberts, married Nadine Alexander in 1940, and served as Sheriff of Honolulu from 1935 to 1961.

• For the Australian exhibition he carved a new board from sugar pine bought at a local hardware store.
• On June 14, 1925 at Newport Beach, California, he pulled eight men from a capsized fishing boat using his surfboard.
• That rescue helped make the surfboard a standard lifeguard tool.
• His name is on Duncan v. Kahanamoku, the 1946 Supreme Court case that ruled against trying civilians in military tribunals in wartime Hawaii.
• His 1990 bronze statue in Waikiki faces the street rather than the ocean, arms open to welcome visitors.