In deep water, particles of water just move in circles. They don’t actually move closer to shore with the energy of the waves. However, near the shore where the water is shallow, the waves behave differently. Look at the Figure below . You can see how the waves start to drag on the bottom in shallow water. This creates friction that slows down the bottoms of the waves, while the tops of the waves keep moving at the same speed. The difference in speed causes the waves to get steeper until they topple over and break. The crashing waves carry water onto the shore as surf.
Bob had seen the ocean before but only from the shore. He had always associated the ocean with waves moving towards him. Now he was on a boat for the first time he was awed by how still the water appeared to be. His friend told him that the water moved in circles here.
What do waves carry onto the shore?