Attached Link: http://www.castleposer.co.uk/free.html

I would experiment with the transperency falloff, but since falloff only applies to a surface's transperency as it is seen at oblique angles, I would think that it would have either no effect or would ruin it. I'm assuming that the water is being viewed at an oblique angle such as from the POV of some one standing on the shore. As far as tutorials are concerned, I don't know of any. hopefully some one will read this thread and post a link to one. I did stumble across a link yesterday in the forum to castleposer. There are free node based texture modifiers offered at this site, along with some excellent tutorials on similar subjects. The texture modifiers make gradations from P nodes in exactly the way I stated above. If you play around with the math funcions and the variables you should get what you want.