Abstract
When the natural light waves travel into the interface between water and air a part of the light waves refracts and diffracts at the interface. When these waves travel to the horizontal observation plane located at the bottom of the water these waves make the light intensity profile in this observation plane. It is possible to calculate the wave profile by applying Suzuki-Sumino's method to the light intensity profile observed at the bottom in the shallow water. When it becomes deeper the wave profile can be estimated using the relation between the gradient of the water surface and the intensity gradient of light observed at the bottom.
