I said I would have a go (at manifesting Dune's explanation of creating foam), and so I did. And I have to say I'm quite pleased at how it turned out.
So below is the render, the tgd file, and a screen shot of how I interpreted Dune's explanation of the node configuration.
Now I'm busying myself with reverse engineering Dune's Basic Surf Setup. :)
I replaced the Sin scalar function with a Cos scalar, and with values of 90 and 55 in Constant scalars 1 & 2 respectively
I got this deep coastal wash.
Sounds like I'm plugging OMO or Daz detergents (remember those you older Terrageners?). ;D
Good start. With water at different levels you need to adjust the color adjust values accordingly, or use an 'add scalar' and some constant value after the 'displ to scalar'. And it's often easier if you stretch the Y of an initial terrain PF. I still have to find a way to get surf on a slight angle (from wind) hitting a coast, but then consistently. And make a mix so they don't appear in long simple lines.