I wanna make water and waves for my little 2D PC game like in this video: http://www.youtube.com/watch?v=ooU6cTeirlQ I don't know how to write a similar shader. Does anybody know how to write a similar shader? Or is it possible to do the waves without shaders?
It's hard to tell how this is made exactly (except by the developer), but let me summarize what has already been said in comments, with some additions:
Additionally, to perfect the illusion, you have some animated sprites for the dolphin splashes, and a trail that seems to be a textured quad strip.