In the scene where Sam Worthington fell out of the boat, the shoot was delayed as there were reports of a five metre long crocodile spotted in the area. After several hours of Worthington terrified to enter the water and ruining the takes, writer/director Greg McLean decided to jump into the water and have a swim to convince him to do it properly. It was only after the scene was shot that they found out the crocodile had been relocated several weeks earlier.
The crocodile photos in the bar are real.
The rope sequence was shot over the course of four nights.