The opening story of the helo rescue gone bad was loosely based on a real event that occurred August 7, 1981. The crew of CG1471 from Airsta Kodiak was responding to a distress call of a fishing vessel near Prince William Sound. As the crew attempted to hoist the survivors of the boat, a wave hit the tail of CG1471 causing the helo to crash into the seas. A painting named "So Others May Live" hangs on CG Airsta Kodiak depicting the rescue.
Chief Flythe, played by Joseph 'Butch' Flythe, who can be seen in various scenes throughout the film, was one of the first five operating rescue swimmers in the Coast Guard, graduating from A school in 1984 and beginning his work at the Elizabeth City base in 1985.
Part of the movie was filmed in the pool at Louisiana State University of Shreveport, and the local Olympic Weightlifting club was forced to train outside of the building during filming because their location across the hall made too much noise when athletes dropped the weights.
(at around 51 mins) In one of the sequences, stunt coordinator Alex Daniels was shown in a picture hung up on the wall where Ashton Kutcher was looking. The photo of Daniels was taken in his years spent as a lifeguard.
The commanding officer of the Kodiak Alaska Coast Guard Station is named Captain Hadley. The same actor (Clancy Brown) also played the senior prison guard in The Shawshank Redemption, named Captain Byron Hadley.
The trivia item below may give away important plot points.
A prominent scene in the movie's trailer, where Fisch tells Randall, "That is definitely NOT in the manual!" isn't in the theatrical release of the film because it actually comes from an alternate ending. In the alternate ending, Fisch successfully holds onto Randall's fingertips, getting him into the helicopter and saving him. The writer, director, producer, and others involved in the film preferred the ending where Randall dies, as it had more emotional impact.