Reeling with grief in the wake of a mission gone tragically wrong, legendary Rescue Swimmer Ben Randall (Costner) is given a mission he doesn’t want - training raw recruits. Once there, he knocks heads with cocky Jake Fischer (Kutcher), a swimming champ driven by a painful secret, who’s more interested in breaking Ben’s records than saving lives. But Ben also sees Jake has what it takes to be the best of the best. Filled with spectacular rescues in the lethal waters of the Bering Sea, THE GUARDIAN is a riveting and compelling story that dives straight into the heart and soul of real heroes, the unsung guardians of the sea.

Overlong, cliche-ridden "Top Gun" of the water, with Costner as the old veteran, and Kutcher as the "up and coming" new boy. Despite all that, a watchable movie, interesting for those like myself with little idea of the work of this particular branch of the Coast Guard. Rescue scenes are tense and exciting, although the special effects in some scenes were a little lame.
Both leads do a reasonable job.