"First Descent" follows five champion snowboarders as they gather in the backcountry of Alaska for some high-altitude, technically challenging freestyle boarding. Like skateboarding and surfing, the sport has its revered heroes and bright, young stars, and both generations are represented in this documentary, which features veterans Nick Perata and Shawn Farmer, world champion Terje Haakonsen and up-and-comers Shaun White and Hannah Teter. The group, which spans in age from 18 to 40, sets out daily in helicopters to find the most challenging mountain runs, or "lines"; filmmakers Kemp Curley and Kevin Harrison intersperse scenes of their trip with talking-head interviews about the sport's history and eventual commercial impact.

Despite some breathtaking photography and at least two genuinely gripping and poetic scenes, Curley and Harrison 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.

Snowboarding aficionados will no doubt value "First Descent" for the chance to see some highly accomplished athletes do their thing on the wide screen. 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. But by and large, the half-pipe swoops, wipe-outs and 360-degree turns that characterize snowboarding begin to all look the same, and 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.

-- Ann Hornaday