Directed by Stacy Peralta. Featuring Greg Noll and Laird John Hamilton. Rated PG.

What is it about humans that makes us want to supersize everything?

Everybody seemingly wants to go the farthest distance, climb the highest mountain, and amass the greatest quantity of whatever precious substance is going. Big-wave surfers, arguably, want to do all of the above and then some. That's the contention of Riding Giants cowriter-director Stacy Peralta, who is even more persuasive here than he was in Dogtown and Z-Boys, which explored the primitive 1970s relationship between surfing and skateboarding.

Here, Peralta goes back further--more than 1,500 years--to the roots of Hawaii's second-biggest export. But things really take off when, after an amusing preamble with Pythonesque animation, Peralta washes up in the 1950s, when proto-beatniks from Southern California made their first, decisive treks to the north shore of Oahu. The Banzai Pipeline, Sunset Beach, and the ominous Waimea Bay became iconic to the looming counterculture via creative entities like the Beach Boys and kitsch efforts like the Gidget movies.

It wasn't all Sandra Dee and "Little Deuce Coupes", though. As one veteran observer states, the guys who lived on the sand "resembled other alternative cultures, like Kerouac and biker gangs--except that surfers were having fun". As in Dogtown, recently filmed talking heads alternate with diligently researched archival footage, photos, and the odd illustration. Here, veterans like barrel-chested Greg "Da Bull" Noll, who scaled the hairiest Oahu heights, and Jeff Clark, who brought a grungy determination to taming Northern California's rocky swells, are filmed on different stocks to visually reflect their eras.

Although Noll dominates the early stuff, Laird John Hamilton emerges as the bronze god of our own time. Starting as a blond sprog inseparable from his older heroes, his big-wave grace and bravery quickly evolved into a daredevil spirit that has seen him attacking places others have mostly avoided.

Still, Hamilton's ventures into tow surfing and helicopter-assisted boarding come across as less soulful developments than the man-and-plank variety that characterize the sport. And, by the way, we definitely meant to say man: only one woman is interviewed here, and little of her surfing is seen. There is also a paucity of Hawaiians on display, although everyone gives fealty to Duke Kahanamoku and other island pioneers.

Another slight deficit comes in the tendency for witnesses to get overly emphatic, not to mention repetitive, in descriptions of experiences or in their devotion to other surfers. The spiritual qualities of the sport are more than amply conveyed by spectacular cinematography supported by perfectly chosen music, ranging from Ventures-type twang to more contemplative sounds from our own time. Riding Giants might not inspire you to hang 10 on 80-footers, but it does renew your respect for the power of nature--and for the ingenuity of people to stand on top of it and scream.