The film opens with a description of a legend told by survivors of being lost at sea: a presence, referred to as the Guardian, which pushed them to the surface, enabling them to survive until help arrived.

Ben Randall is the top rescue swimmer at the United States Coast Guard's Aviation Survival Technician (AST) program, but the long hours have destroyed his marriage.

Shaken by survivor guilt, Ben is transferred to become an instructor at the Coast Guard AST training school in Louisiana, where he develops a legendary reputation among the students for his high number of rescues.

One student is hot-shot candidate Jake Fischer, a top high school competitive swimmer who rejected scholarships to every Ivy League college to enlist in the Coast Guard.

During training, Jake meets local school teacher, Emily Thomas, and they begin a casual relationship.

They bond over their experiences as sole survivors and return to the bar, where Ben defeats a seaman harassing them, forcing the rest to stand down.

Emily attends his graduation, but they end their relationship because Jake is leaving for an assignment at CG Air Station Kodiak, Alaska, Ben's previous post.

Jake is sent to rescue the crew of a sinking fishing trawler, but he becomes trapped in the hold trying to save the captain, who is killed by debris.

His helicopter is forced to return to base, where Ben hears of the situation and decides to suit up and rescue Jake personally.

The end credits are replete with "glory" shots of U.S. Coast Guard helicopters conducting rescues in the greater New Orleans area.

An airman is the enlisted rating of a Coast Guardsman who is undesignated and/or currently undergoing training in an aviation related field.

[8] Stephen Hunter pans it in The Washington Post, calling it "a good little film" for the first hour then it "begins to overload its frail reed of a structure with giant sloppages of cliches from other movies, some so bad it's almost comical", concluding that the movie "veers off into slobbery touchy-feeliness, and the tone becomes mock-religious, almost liturgical.

"[11] In a Variety review, Joe Leydon says the movie is "overlong but [the] involving drama has obvious cross-generational appeal.

"[12] Ed Blank in the Pittsburgh Tribune-Review gave a mixed review, saying "The Guardian regurgitates formulaic elements in a way that pays off repeatedly and potently.