I don’t know if it’s possible but can you add a dynamic object (A cube) and allow the water to push it along. I’ve tried various things but no success. Just wondering if there is any solution.
I believe you can have animated obstacles, but the fluid does not apply force to the obstacle. So you can fake it. Animate a cube moving (or create keys from a dynamic simulation) then time that IPO with the fluid. It does go the other way round, however, your mesh can “Stir/Affect” the fluid.
Here is my example of an animated mesh interacting with a fluid simulation.