you land on the waves? >> depending on the wind and water, i would always want to land parallel to the swells so if your waves are coming this way, you want to land on the top. you never, ever want to be into -- this is what's called a cross-swell, where you're perpendicular into the water this way. >> what might happen? >> if you land into the face of the swell, you could actually flip over like this. that's not a good thing. >> another potential hazard that could have spelled disaster for flight 1549, coming down with one wing higher than the other. >> the airplane could have cartwheeled and that would have been very violent and significantly lessened the opportunity to get everybody out as well as they did. >> cactus 1529 turn right, 280. you can land runway teterboro. >> we can't do it. >> okay, which runway would you like at teterboro? >> we're going to be in the hudson. >> the captain just said, brace for impact. everyone started saying prayers, just looking at each other, not knowing what to say, what to do.