Bethany Hamilton, one of the world's most popular female surfers, said Sunday she will not compete in World Surf League events if it goes forward with a rule change allowing biological males who identify as female to compete.

The WSL, the governing body for professional surfing, announced last week that biological males could compete in women's events if they maintained a testosterone level of less than five nmol/L (nanomoles per liter) for the previous 12 months, according to a report in The Inertia.