I think it's that shape bloodsong because when a wave comes ashore and you are close enough to see it, it causes turbulence underwater too by current that's flowing in a different direction. There will be color shifts and shapes under the water too, so I think that is why the shape is this way. It should cause irregular refractions and reflections when there is another wave in front or behind it, making those nice color differences. I think ;). Laurie