In one underwater scene, Olivia Wilde's character Bea can be seen panicking while trying to find an air bubble. This is actually real, as Wilde missed her mark and could not locate the air bubble. Because it was a wide shot, the safety divers were too far away to get there. But she eventually found the air pocket.
A real surgeon did the organ removal sequence.
The entire film was shot on location in Brazil.
The crashing of the bus was done in one take.
John Stockwell: at the end of the movie, he's the backpacker arguing with his girlfriend over whether to take the bus or the plane.