Battle of the Boards on Cali's Beaches

"I have no interest in trying SUP," says Chris Dewind, a devoted shortboarder and college student from Malibu. "You see these SUP riders sitting way outside or on the shoulder [of a point break], and they just don't care about the other surfers."

Mr. Dewind admits that it is more difficult to catch a wave on a shortboard than a SUP, but "I still think they should go find their own peaks – away from traditional surfers."

Still, not everyone believes there needs to be segregated surf zones. Greg Bonann, a Los Angeles County lifeguard and creator of the TV series "Baywatch," draws a comparison between SUVs and smaller cars.

"One is bigger, and you don't want to get hit by it, but there is no reason that you can't share the road together," Mr. Bonann says. Then he offers a piece of pure laid-back L.A. advice to SUPs: "Surf politely, enjoy one another, and enjoy the waves."