The U.S. Coast Guard rescue-swimmers at the center of The Guardian may be able to save you from a raging current or a hurricane swell, but even they can’t help succumbing to the movie’s torrent of watery clichés: an over-the-hill vet (Kevin Costner) haunted by a deadly mishap, his cocky but immature protégé (Ashton Kutcher), the inevitable clash between old school and new. And that’s just the first 20 minutes! Directed by Andrew Davis ( The Fugitive), the movie is scaled as an epic, but plays like a 1940s pro-military quickie decked out with more padding than a Berber carpet. And while Davis remains an adept handler of action scenes, his evident fatigue with the material is the sort of thing that can make a movie sink faster than muscle in the pool. There are momentary pleasures here, chiefly Costner, who’s aged very nicely into playing former golden boys. But at nearly two and a half hours, The Guardian is neither serious enough to take seriously nor flashy enough to get by on thrills alone. Jerry Bruckheimer, where art thou?