Jaws

Analyzing the scene I can tell it is very scary. One thing that can contribute to it being scary is the dark night back round the director portrays to show. You can also tell things are about to get scary when the girl is screaming and the boy isn't moving to go help her while she is being attacked in the dark by something no one can see. Also the fact that she is desperatly trying to save herself by clinging onto the buoy and she just gets ripped off of it. What's even more scary is when she disappears into the dark water and doesn't come back down.