I am currently working on a riser piping which enters a platform. most of the piping is exposed to wind and wave at the same time. I just want to make sure if CII considers wave load on the piping system up until its "height" eventhough the wind is set for the piping from where it comes out of the water (El. 0.00).
could anyone confirm?

Most of the wave theories stop at the free surface. However, the "Modified" theories in CAESAR II, as well as the Stream Function theory do determine the fluid particle motion all the way up to the actual surface elevation.

I suggest you use smaller element lengths in this region, since an element is exposed to either wave or wind, but not both.