In an early scene, Ann Marie is brushing her teeth, looking in the mirror. Her eyes are natural: one hazel, one blue. During the surf competition, her eyes are both hazel. On the movie poster, her eyes are blue.
During the competition, Anne Marie removes the leash from her leg when is under the water so she can surface. Later, after the third wave hits, we can see her rolling under water with the yellow leash attached to her.
The last time the girls pull up beside Matt while chasing him down the highway, you can see a car ahead coming towards them in the distance, and yet they have time to have a conversation before it reaches them.
When Anne Marie is telling the girls about her time with Matt, the first time after the group surfing lesson, all of the girls are sitting on the bed barefoot. In the next shot, two of them are wearing flip-flops.