What happens when a wave breaks?

Question

What happens when a wave breaks?

Answer 1

Basically it trips over its own feet and falls forward.  The bottom of the wave hits the floor of the water body, which slows down the bottom of the wave but the top keeps on going.  Eventually and pretty quickly usually the top is no longer over the bottom, but is out in front, and tumbles down.

Answer 2

Waves extend below the water surface, and since they have lots of room where the water is deep, you don't much notice them unless the wind is blowing. As they approach the shore, they start running out of room below the surface, so they start pushing up above the surface. A wave breaking is essentially its collapsing from its own weight; it has no more room below the surface, and it can no longer sustain itself above the surface. The characteristics of waves are directly related to the shoreline.