I remember being on a looooong walk on some Danish dike when my sister was small and really didn’t want to walk any more, telling her about how phase velocity of shallow water waves depended on water depth and how you could observe that when waves are refracted towards the coast (assuming the sea floor has the right slope). And whenever I see this happening now I have to think of that freezing cold and windy day a long time ago.

Wave fronts turning towards the shore

Watch how the angle of the wave fronts changes as they come closer to the shore: