Question: What sport do both Isabel Letham and Duke Kahanamoku have in common?
Sentence (from "Isabel Letham"): Isabel Letham (23 May 1899 – 11 March 1995) was an Australian pioneer surfboard rider and swimming instructor, renowned as 'the first Australian to ride a surfboard' (although she disputed that claim - Isma Amor of Manly is believed to be the first Australian Female Surfer and Tommy Walker of Manly is believed to be the first Australian Male Surfer).
Relevant evidence: Yes