"It is believed that the surface of water has always the same height . . . but, it is not always true . . .
Here, We see the smooth part slightly higher - seems to "dive" when it encounters pebbles. It is all about speed - like You . . . when You lean on Your bike to go faster, You take the speed. In doing this, the water keeps the pebbles glued together, like the wind plate Your clothes when You pedal"

Chris Frig - Corsica