A strange title, but when I was putting this together, I thought it would be nice to be able to 'blur' certain parts of a model. Like the rotor, which was post in PS here. Perhaps a fine alpha channel for opacity could do that, but I have to dive into that again. There were some threads regarding this, but I wasn't able to find them.
The image title is also strange, as I was first making an abyss for the heli to hover above, later adding some water. And the real truth is that I just wanted to test out a new tree I made.... so never mind the ugly ground surface.