I implemented a basic water simulation a very long time ago. The water was approximated using a matrix of vertices where each vertex behaved like a spring and a

I implemented a basic water simulation a very long time ago. The water was approximated using a matrix of vertices where each vertex behaved like a spring and affected its neighboring vertices. So for example clicking a spot in the water would pull the closest vertex down and it would spring back creating a domino affect with its neighbors, their neighbors' neighbors, etc. It looks like this is using a similar technique which is why you occasionally see those steep "spikes".