The aim of the documentary "First Descent" is clear: It wants to do for snowboarding what the films "Dogtown and Z-Boys" and "Riding Giants" did for skateboarding and big-wave surfing.

But those two movies had some crucial things that this one doesn't, namely a skilled director (both were made by the former skateboard star Stacy Peralta) and casts of colorful, compelling characters. Despite some breathtaking photography and at least two genuinely gripping and poetic scenes, Kemp Curley and Kevin Harrison, the filmmakers behind "First Descent," have created a surprisingly tedious, overblown defense of a sport that, while ushering in the era of "extreme" games, doesn't boast the cinematic potential or charismatic stars of its cousins on the asphalt and aquatic waves.

The film follows five champion snowboarders as they gather in the backcountry of Alaska for some high-altitude, technically challenging freestyle boarding. For the uninitiated, a brief primer: Snowboarding, invented in the 1970s, involves schussing down the slopes with both feet on one wide ski, an arrangement that allows for more improvisation and death-defying tricks and jumps than typical skiing. (Those of us old enough might remember the Snurf, a 1970s toy that was a kind of prototype for modern-day snowboards.)

After early years experimenting on the margins of winter sports and feuding with downhill skiers who had trouble accepting the in-your-face antics of the young arrivistes, snowboarding finally came into its own in the 1990s, when it was the centerpiece of ESPN's Winter X Games and an Olympic sport in 1998. (There's admittedly something special about a sport in which one of its first Olympic competitors is disqualified for doping, not with steroids but with pot.)

Like their skateboarding and surfing cousins, snowboarders use words like "gnarly" and "hairy" and "sick" to describe their experiences (those are all terms of approbation, by the way), and they've borrowed many of those sports' graceful, gravity-defying moves. Likewise, snowboarding has its revered heroes and bright young stars. Both generations are represented in "First Descent," which features veterans Nick Perata and Shawn Farmer, world champion Terje Haakonsen and up-and-comers Shaun White and Hannah Teter. The group, which ranges in age from 18 to 40, sets out daily in helicopters to find the most challenging mountain runs, or "lines"; Curley and Harrison intersperse scenes of their trip with talking-head interviews about the sport's history and eventual commercial impact. (The three-week trip to Alaska was arranged by the filmmakers.)

Snowboarding aficionados will no doubt value "First Descent" for the chance to see some highly accomplished athletes do their thing on the wide screen (until now, snowboarding has mainly been the purview of DIY videos whose gonzo party stunts gained them a huge cult following and are credited with helping the sport catch on). And there are some admittedly arresting scenes, including one of a snowboarder named Travis Rice -- who joins the Alaska group mid-trip -- being engulfed and finally outrunning an avalanche, and Haakonsen dominating Mount 7601, which is named for its height.

But by and large, the half-pipe swoops, wipeouts and 360 turns that characterize snowboarding begin to all look the same, as Curley and Harrison return again and again to the same events and competitions. Unlike the streets and swimming pools of Southern California or the turquoise breakers of Hawaii, snowscapes -- whether they're in Vermont, Colorado or Alaska -- tend to look the same up close: white. And it's often difficult to discern who's who underneath the parkas and sun goggles.

What's more, the stars of "First Descent" aren't particularly memorable, or even likable. At their worst they come off as cocky, self-absorbed Peter Pans; at their best, they're sweet but shallow. "Dogtown and Z-Boys" may have just been about skateboarding, but in Peralta's hands it became much more, as it documented the rise of a larger social and cultural movement, as well as a disappearing place and time. By comparison, "First Descent" is just a bunch of guys, and the occasional girl, playing in the snow (and why do they all look like Owen Wilson?). To use the sport's own lingua franca, "First Descent" just isn't sick enough.

First Descent (110 minutes, at area theaters) is rated PG-13 for brief strong language and a drug reference.

World champion Terje Haakonsen is featured in the surprisingly tedious snowboarding documentary "First Descent."