"It's time for me to rescue myself!"

There you have it, your theme, tidily delivered in one line of dialogue. This is a movie about people rescuing themselves from figurative traps. Of course, most movies don't actually come out and SAY what their message is. Most movies like you to gradually understand what they're all about by watching the story and letting yourself become caught up in the characters' lives. But not "The Guardian"! Here we wear our hearts on our sleeves, lest anyone miss the point.

It's that earnest naivete that makes the film rather charming, actually, if over-simple and at least 30 minutes too long. Directed by Andrew Davis ("The Fugitive") from a screenplay by Ron L. Brinkerhoff, the movie has no agenda other than telling an ordinary story about two Coast Guard swimmers, one a veteran and one a rookie, and telling it in a straightforward manner.

The veteran is Ben Randall (Kevin Costner), married to Helen (Sela Ward) but really married to his job. They're stationed in Kokiak, Alaska, where Ben spends every waking hour on duty, rescuing stranded kayakers and storm-tossed fishermen from watery peril. As the film begins, Helen is walking out on Ben, jealous of the attention he pays his job over her. "I"m not some nameless drowning victim," she says, right before the bit about rescuing herself.

As if that weren't enough, Ben barely survives a disastrous rescue mission next, prompting his captain (Clancy Brown) to suggest a break. Ben takes a job at the Coast Guard academy, where he'll teach eager new recruits how to save lives in icy waters.

The cockiest of his new students, the one already bragging he's going to beat all the records set 20 years ago by this "Ben Randall" person, is Jake Fischer (Ashton Kutcher). Jake was a swim team champion in high school, and much of his confidence is justified. But he'll need some humility and discipline if he's going to become one of the Coast Guard's elite. You might even say he needs a father figure, a mentor, if you will.

The movie takes us through the usual paces of training and camaraderie-building, including an obligatory (but quite unnecessary) subplot in which Jake picks up on a local girl, a schoolteacher named Emily (Melissa Sagemiller). Considering he will soon leave the training camp and be posted elsewhere, the romance seems particularly doomed. And in a movie as over-long as this one, I'd say the romance angle should have been the first thing cut.

With Jake successfully graduated and sent out into the field, and with Ben having healed some of his own psychic wounds and ready to move on, the film reaches its stirring finale. It's a good one, not as predictably formulaic as the rest of the movie, worth waiting for through all the speechifying and mentoring that takes place earlier.

After some poor choices, Kevin Costner's last few films ("Open Range" and "The Upside of Anger," particularly) have re-earned him our affection, and "The Guardian" should extend that streak of goodwill. He's his old likable, laconic self again, neither grandstanding nor slacking in the acting department.

His co-star Ashton Kutcher shows more maturity than we'd given him credit for, delivering a performance that is a good deal more adequate than you'd expect from the goofy former model. Is he brilliant? No. Like the movie itself, his performance is personable and good-natured ... and nothing special. Is that enough? It's borderline, but sometimes "nothing special" is OK.