Zac Efron acts in 'Charlie St. Cloud'

It isn't easy for a teen heartthrob to become a serious thespian, but one way is to star in a weepy romantic drama, a genre that calls for much actorly emoting. As a bonus, it also appeals to girlish fantasies of love and tragedy.

When it works, you get a box-office smash like "Love Story" (1970), which put soap star Ryan O'Neal atop the A-list, or 1997's "Titanic," which vaulted Leonardo DiCaprio into the stratosphere. When it doesn't work, you get this year's "Remember Me," a flop that seemed to seal Robert Pattinson into his "Twilight" coffin.

Zac Efron, the prettiest face in Disney's "High School Musical" franchise, makes his bid for credibility with "Charlie St. Cloud," adapted from a 2004 novel by Ben Sherwood. Efron plays the title role, a small-town teenager headed to Stanford on a sailing scholarship. But after a terrible car crash, Charlie stays home to keep the ghost of his little brother, Sam (newcomer Charlie Tahan), alive in his memory. It will take a pretty local girl (Amanda Crew) to help him overcome his guilt and right his metaphorical ship.

Efron spends a lot of time looking gorgeously wounded, but his scintillating blue eyes also reveal intelligence and humor. And while director Burr Steers ("17 Again," also with Efron) has a duty to wring tears, he also allows his actors time to build their characters. Efron's scenes with Tahan, in which they frolic and fight and make up, can be quite moving.

Efron fans, at least, will surely root for Charlie to resume his sailing career. After all, that's when his shirt gets wet.