Textures in the Sand Kids Hoodie

What is this? While walking on the beach at Punta Cana in the Dominican Republic, I couldn't help but notice the patterns left in the sand after the waves receded. The sand there was very coarse, I think it's the kind of sand formed by the waves grinding up trillions of sea shells, which easily flows with the passing of each wave. In this, you can see the passing of probably three waves, which left fine etchings in the sand as the water receded but you can also see the line left when a wave reached its maximum flow up the beach.