A new movie explores the life and work ethic of surfing star Laird Hamilton, who worked to overcome every limit the ocean tossed at him. (Sundance Selects/Sundance Selects)

It takes a lot of work to be a surf bum.

"Take Every Wave: The Life of Laird Hamilton," the latest documentary from Rory Kennedy ("Last Days in Vietnam"), is partly the life story of Hamilton, widely considered the world's best big-wave surfer, and partly a study in obsession. Kennedy bounces back and forth between times in Hamilton's life: his unconventional upbringing on Oahu, his surfing career and his startlingly ordinary (and very wealthy) family life with volleyball player Gabrielle Reece and their daughters.

What ties all the time-hopping together is Hamilton's drive to push against every limit the ocean puts in front of him. While the nonlinear structure gives a good sense of Hamilton's journey from counter­culture to mainstream culture, it also means that "Take Every Wave" lacks narrative focus. Kennedy is skilled at interweaving home movies and video shot by Hamilton's Strapped Crew — a group of men who developed tow-in surfing, where water scooters pull riders to waves that are unreachable by paddling alone. But the intimate, immediate style of the Strapped Crew's work outshines much of Kennedy's original footage.

What's more, there's little sense of revelation. Although Hamilton — who is not widely known to a general audience — is inarguably a legend in his sport, and an engaging enough subject, "Take Every Wave" doesn't give us a reason to invest deeply in his story. The film's last shot is a gasp-inducing long look at Hamilton triumphantly skimming across a wave for what seems like minutes. In the end, that ride isn't worth the work it takes to get there.

Unrated. At Landmark's E Street Cinema. Contains strong language. 118 minutes.