About 75 percent of "Message In a Bottle" is waiting for the other shoe to drop.

Robin Wright Penn plays a Chicago Tribune researcher who becomes fixated on finding the author of a grief-filled love letter set adrift at sea. By the time she meets him, the letter has done a number on her heart and she falls in love quickly with the achingly widowed, middle-aged salt, played by a Kevin Costner, and spends most of the movie trying to find the right moment to say "Hey, I read that letter to your dead wife that no one was ever supposed to see."

For me it was hard to overlook the fact that, from a journalism ethics point of view, she should have told him right off the bat since her trip to his North Carolina fishing town was, in part, job-related -- after finding the letter on the beach, she gushes over it at the office and it finds it way into print, spawning a huge response from the lonely hearts crowd.

But this incessant anticipation, which must inevitably lead to Costner hitting the roof when he discovers his correspondence in her dresser drawer, is forgivable when upstaged by a powerful cast.

Penn gives a extraordinarily natural performance. Honest, compelling and fervent, even her breathing changes subtly when she is overcome by emotions she did not anticipate. She understatedly carries the movie and I can't think of any other actress who would have been better for the part.

Costner is in the kind of role that brings out the best in him, as a hesitant and heartbroken husband content to spend his days pining for his dead wife, until he meets Penn and isn't at all sure what to do with his sentiments. His deliberate restraint and serious-but-winsome romanticism is as engaging here as it is in all his most memorable roles, like "Field of Dreams" or "Bull Durham."

And as the comic relief and voice of experience, Paul Newman is perfectly cast as Costner's father, a charmingly grouchy, reformed drunk. He would be an Best Supporting Actor shoo-in had this movie been released two months ago.

Based on a 1998 best seller by Nicholas Sparks, "Message In a Bottle" is an adult romantic drama about coming to terms with love and loss, and finding one's peace with the world. Gently manipulative and beautifully structured, director Luis Mandoki ("When a Man Loves a Woman") manages to avoid succumbing entirely to the chick flick undertow, even in Lilith Faire love scenes with moonlit close-ups of kisses and hands on golden skin.

He keeps the galloping metaphors fairly bridled, as well. Costner, who restores boats for a living, sails to clear his head and after meeting Penn begins working on a custom boat he'd abandon after his wife died.

Thanks to Mandoki's balance, none of this emotional machination inspires the kind of eye-rolling witnessed in recent, pointed tear-jerkers like "Stepmom" and "Patch Adams," even when he does doubles up on the hankie-wringing for a last reel of emotional spiraling.

Uncharacteristic contrivances, such as our heroine's excruciatingly slow recognition of Costner's obvious emotional baggage, and a several flagrant journalistic credibility problems dog "Message In a Bottle." But ultimately Mandoki's transporting direction, Caleb Deschanel's fluid seacoast cinematography and the stars' sensitive molding of their hesitant lovers preempt the film's problems and give "Message" a moving current that sweeps the audience along even as we take note of its imperfections.