In a linear shear flow with the free surface being a solitary wave, shall this free surface solitary wave profile coincides with a streamline representing the flow? I have plotted out the streamline of the flow. The streamlines look like the profile of a solitary wave. However the streamline corresponding to the free surface do not really coincides the solitary wave profile exactly. I am wondering if it is an error with my computation or what. What comments do you have?