(FORTUNE Magazine) – Surfing isn't fun unless it's dangerous. I got injured last Easter at my house on the north shore of Hawaii. I pulled my hamstring--tore it two inches off the bone. I'm still recovering from that. But people also get speared by other boards. You don't want to cut people off when you get a wave. I had a guy kick his board out [on purpose] and cut my leg. I guess I cut him off. So I said, "I'm sick of this." I found an aikido karate expert and said he could be a consultant on one of my television shows if he'd teach me aikido karate. That gave me more confidence with the guys in the ocean. You want to feel like you can defend yourself.

Tom Hanks and I used to watch the surfers at Malibu, and we thought it looked fun. But we watched year after year without quite being ready to enter the tribe. Hanks is the one who said, "Hey, we gotta do it--we have to jump in." It was like a birthday dare. Now I have two surf tribes--one in Malibu, one in Hawaii. The one in Malibu is about ten guys and five girls, and they have nothing to do with show business.

When I made the movie Blue Crush, I wanted to do a woman-empowerment movie, and I liked the tribal surfing. I also wanted to enrich my status within the tribe. So I thought, Why don't I just make a movie about one of my passions and enable myself to get a better position on the wave?