I have seen the same thing. and yes, to me it looks like water flowing in a stream!Yes Sir, when the wind slows up I start seeing a heavy mirage on the target, my shot goes high. I've started picking up on it and just hold low to compensate. It's been working out for me. I've had others call it a mirage boil. The way it looks does remind me of water at a slow boil.....you can see a current moving in it.