On Thursday, 24 December 1914, an athletic young Hawaiian strode across the beach at Freshwater, a stretch of sand between Manly and Curl Curl. The day was clear and sunny, and Duke Kahanamoku was about to perform a feat never before seen in Australia.

Kahanamoku was 25, a Waikiki beach boy whose "flutter kick" had won him a gold medal for the American team at the 1912 Stockholm Olympics and an invitation from the New South Wales Swimming Association to demonstrate his technique at a meet at the Domain Baths. He was also invited to give a display of "board-shooting", a novelty which the aquatic-minded Australians were keen to witness. There being no surfboards in the country, Kahanamoku constructed one from a solid plank of local sugar pine.

By the time he entered the water a sizeable crowd had gathered, including a local schoolgirl and avid ocean swimmer, Isabel Letham. Rapidly outpacing his escort of lifesavers, Kahanamoku paddled through the breakers, sat on his board in the calm beyond the surf line and awaited a suitable wave. When it came, he swung the board around and glided all the way to the shore, kneeling at first, then standing. It was, the Sydney Morning Herald reported the next day, "wonderfully clever". When Kahanamoku called for a volunteer to help demonstrate tandem surfing, Letham was first in line.

The bronzed Hawaiian with the mane of black hair and full-sail shoulders made it seem easy, but when the 15-year-old Australian looked down from the crest into the trough, she thought she was "going over a cliff". For three waves she resisted Kahanamoku's attempts to get her upright. Finally, he yanked her to her feet. After that, she was "hooked for life". When Duke Kahanamoku returned to Sydney after competing in a slate of eastern-state swim meets, Isabel Letham rode with him at Dee Why, amid considerable publicity.

Australia had a new enthusiasm and its first surfer had an international profile. Fearless, forthright and glamorous, Letham headed to America. San Francisco appointed her its director of swimming, but the Manly Surf Club's refusal to grant membership to a woman left Letham without credentials as a lifesaver and stymied her attempt to establish Australian-style lifesaving clubs there. She returned home to teach water ballet. When she died, in 1995, her ashes were consigned to the waves by a circle of board riders.

Duke Kahanamoku is remembered as the Big Kahuna, the father of modern surfing. His original board has pride of place in the Freshwater Surf Lifesaving Club.