We can physically move vertices in the vertex shader to create wave effects. If your meshes are too low-poly, you can subdivide them with tessellation to improve the fidelity.
Scene intersections can be used to make foamy water along coastal edges and glowing edges on objects which pass through other objects.
Along with coloring pixels, we can modify the vertices of a mesh in-shader to create wave displacement effects, amongst other things.
This quick-fire article will blast through ten effects, from inverted hull outlines and silhouettes to vertex displacement waves and 2D swirling vortices.
Surfing the seas in Zelda Wind Waker is so iconic because of the stylized water effect, which we can recreate with a Voronoi-style noise texture.
With a UV offset based on a flow map texture, you can make the camera feel like it's underwater.
