How to render ocean surface and Foam/splash in different passes

[ben_hamburg]

Title says it all...
Read in another post that its faster to render Foam/splashes without refractive Ocean surface present.
But how do i do this correctly?
just tried to set all objects but the PHXFoam object to Vray matte with Alpha=-1 in Vrayproperties, but the comp didn´t look right. I just checked the refractive Material and I hadn´t checked "Affect colors and Alpha", so that might have been the problem.

[Ivaylo Katev]

add an atmosphere render element, the foam/splash are atmospheres