Here's an example of some of the my more basic water. It uses a normal map sampled twice and offset over time. This allows the map to pan across the UVs, giving the illusion of movement. Used with tilable textures the effect is decent. I offset by sin(time) in one direction and adjust the speed and scale of the second normal map to add a little variation. It also uses alpha blending via a frensel term with a slight bias.
Maya CGFX File:

phongnormalpan.cgfx |
Unity SHADER File

phongnormalpan.shader |