Dest Color/Base Color node in Material Editor?

I’m making an ocean shader for a test project, and I need to sample the base color underneath the translucent surface.

While Depth Fade works great for making the opacity fade out, that will also screw up with the specular lighting on top of the water, so I need to be able to change the actual color of the pixels underneath the surface without changing the material’s opacity. This would be great if I had access to the Gbuffer for the base color, but all I could find was Scene Color, which includes the color of translucent surfaces.

UDK had a Dest color node that allowed this exact functionality. I hope this is not too difficult to bring back.