Do you mean, adding a displacement shader/map to the fluid shader?

I just looked at the docs for any reference to that, and found nothing.
Thanks for bringing that up, because I wanted to do something like that.

However, if you just want to do an effect similar to something rising out of the water, or fluids going around an obstacle, there are tuts in the docs for that.

In that case, also remember:

The fluid container is the basis for any dynamic or non-dynamic fluid effect. (Open water effects do not require containers. For details, see Creating Ocean Effects in the Docs..)

A fluid container is a rectangular 2D or 3D boundary that defines the space in which the fluid exists. Fluid cannot exist outside a container.

When you first create a fluid container, it's empty. To make a fluid effect you add contents to the container and then modify the look and behavior of the fluid by modifying the container attributes.

Also, if you are just doing a still shot, you can convert a fluid to a polygonal mesh, which you can then treat like any other polygon object that can be displaced

Hope this helped a little