Thanks for the kind words.
Yes the grass is animated with a vertex shader.

One frame consists of:

• 9-20ms: shadowmap rendering (though you don't really need to render this every frame, you can easily do this in 6ms on average)
  
• 7-16ms: depthmap rendering
  
• 2ms: rendering 1000 bubbles
  
• 0.1ms: final composing (bloom, blur, volumetric shadow)
  
• the rest is used for calculations and a6 rendering

The bottleneck in this scene is my submarine (the one with the big sphere), it has 10k polys, so when it get renders three time (shadow, depthmap, normal rendering) this is a remarkable slowdown.