AFTER THROWING Harrison Ford off trains and over waterfalls in The Fugitive, 59-year-old director Andrew Davis is no stranger to action. But can he make the leap from nail-biter to lung-burner? In The Guardian, opening September 15 and starring Kevin Costner and Ashton Kutcher, Davis trains his lens on the toughest job in the water: that of a U.S. Coast Guard rescue swimmer. Anthony Cerretani spoke to Davis about keeping it real.

OUTSIDE: So who's the better swimmer, Kutcher or Costner?
DAVIS: Well, Ashton's a lot younger . . .

Fair enough. How'd you get the two prepared?
We had a ten-day boot camp, the real deal, run by guys with the Coast Guard's A-School program. The idea is that you have to push people beyond their capabilities to see how they handle stress.

What kind of stress are we talking about?
It's cold, man. When the chopper's blades are spinning and there's water in the air, it's like being shot with pins of ice. The downdraft is about 120 miles an hour. The noise level? You can't hear anything.

And you had to simulate this.
In certain movies, the ocean doesn't look real—it looks like a tank in a studio. We filmed in the Bering Sea and also built a 100-foot-long tank that generated six-to- seven-foot waves. Then we added huge wind machines that created 40-to-50-mile-per-hour gales.

Do the real Coast Guard rescuers work in those kinds of conditions?
They deal with boats on fire, ships flipping with people trapped inside—they're what we want our heroes to be.

Sounds like these guys do it all.
They're even responsible for all the survival gear on the helicopter—rafts, flares, sewing all the webbing. You can fail out of A-School if you can't run a sewing machine. Imagine not making it because you can't sew.