Watch any surfing documentary, from “Whipped!” to “Riding Giants,” and you’ll hear the dudes speak — in hushed tones — about the treacherous and epic waves that show up off the coast of Northern California when the conditions are just right.

The Mavericks break is legendary, and for years, was considered some sort of myth by those who surfed and had never seen it.

“Chasing Mavericks” is about the days when that break was acknowledged as real, and the teenager — Jay Moriarity — who became famous there.

Jonny Weston is Jay, a curly blond who got the surfing bug from his somewhat standoffish neighbor, Frosty. The older surfer, played by Gerard Butler at his most gruffly charming, has a job — roofing — a gorgeous wife (Abigail Spencer) and a growing family. But his passion is surfing. All flowing locks, a regular Adonis-on-a-long-board, Frosty is one of the “children of the tides,” he poetically narrates. And his secret is Mavericks.

In a brief prologue, we learn of Jay’s working-poor background — his alcoholic, semi-employed divorced mom (Elisabeth Shue) and his absent father.

Jay lionizes Frosty, and stows away on the guy’s ancient Ford Econoline van when Frosty sneaks off to Mavericks, of which only a quartet of veteran surfers are aware. They know what the conditions are and are skilled enough to handle waves as high “as five-story buildings, a thousand tons of water pounding you, holding you down.”

Those are Frosty’s warnings to the boy. But when his wife points out that “there are all kinds of sons,” Frosty mentors the kid — trains him for that magical three-month window when conditions make Mavericks an epic ride.

“Chasing Mavericks” tends toward the cute, But the mentor-student relationship works. And the surfing footage is awe-inspiring. The film captures the majesty and violence of the big waves and gives us a taste of their allure.

It’s a bit overlong, for the limited scope of the story and narrow vision of the characters. That’s probably due to initial director Curtis Hanson getting ill and being replaced by the equally accomplished Michael Apted in the last chunk of the shooting. Either one, on his own, might have ensured those issues were addressed.

But “Chasing Mavericks” is still an entertaining dip into a world many talk about, but few have ever sampled first-hand.