The way waves break depends on a few things. For 1, it depends what sort of bottom its breaking on. In this particular image, the swell has gone over a small rock submerged under just a few inches of water. The rock shape is unique, it is almost shaped like a mini mountain, with a tip at the end. Thats what you see just a thin string like lip of the wave folding over. I was waiting on the side as this wave came through predicting its projection. I always get a big surprise, but this was different. I love the way the lip is lurching forward and over.