What Lies Beneath.
There's no dialog being used in the trailer so it engages the audience in suspense. There is hardly any diegetic sounds being used but this also grabs the audience's attention as the only thing we can hear is the main character and what they're focusing on.
Editting plays an important part in the opening. The title of the film appeared on the screen in the effect of water. This could be done in order to give the audience an insight of what the film would be about, hence the name 'What Lies Beneath'. Suddenly we see the actress' face appear from the water giving the audience a sense of shock. The face is closely zoomed and only focusing around her making her the focus. In my opinion, the fact that her face appeared from under water could possibly be foreshadowing her death or have a subtextual meaning that the audience don't know about.