The reflection of a bright light source on a dynamic surface such as water with waves can be difficult to render well in real time due to reflection aliasing and flickering. In this paper, we propose a solution to this problem by approximating the reflection direction distribution for the water surface as an elliptical Gaussian distribution. Then we analytically integrate the reflection contribution throughout the rendering interval time. Our method can render in real time an animation of the time integrated reflection of a spherical light source on highly dynamic waves with reduced aliasing and flickering.