At the age of 13, standing at 4'11" and weighing 85 pounds, Florence became the youngest surfer ever to compete in the Vans Triple Crown of Surfing, which consists of three big-wave surfing contests in Hawaii. He had previously won five amateur awards, the 2003 1st NSSA Nationals Open Mini Grom, the 2005 1st NSSA Nationals Open Boy's, the 2005 NSSA Open Boys and the Explorer Menehune Champion. He did not pass the first round, but he did score higher than Shane Dorian, a professional surfer twenty years Florence's senior. Afterwards, Florence said he was "pretty scared," but that he was "happy with how [he] did". When Florence was still a youngster, pro surfer Kelly Slater said, "John John's going to know the waves on North Shore like no one we've ever seen before."