There were many small streams, actually they're really too small to be called streams, that came out of the forest and flowed across the sand into the ocean.  So small was the amount of water that no channel was cut in the sand.  Rather the water flowed across the top of the sand and mixed in such a way that they developed these interesting patterns.  These occurred on a number of beaches, yet they were easy to pass up.  I find the grandeur of nature in the little details as often as the grand vistas.