In Cycles, the F12 render has some issues applying dynamic paint to a fluid simulation mesh. The dynamic paint does render in the viewport, but not with the F12 render. When I apply the fluid to the mesh making it a normal mesh, it will render by F12. But then you will loose the animated simulation. I think it must be a bug since the viewport render works on the fluid simulation, but not with the F12 render. Also, after trying to render the scene by F12, the viewport render will not render the dynamic paint anymore. You need to refresh the frame to make the dynamic paint come back in the viewport render.
1: The fluid simulation (dynamic paint canvas)
2: A stationary mesh (dynamic paint brush) which the fluid simulation goes through.
3: Scene rendered in the viewport (works fine)
4: Scene rendered with normal render (F12) (does not render the dynamic paint).
The canvas wetmap is applied to an attribute input that is Fac connected to a mix shader.