1. first of all create a rectangular box just like the pic above. And then create a rectangular plane and dont forget to GROUP it.
2.Usually when installing vray for sketchup there is a default set of materials given with the installer. So the easiest way for me is to create a new material from an imported ones.
3.choose Glass.vismat as it is best resembles the refraction and reflection quality that the water material needed.
4. click on the m to assign a displacement map. and before that ticked on the displacement and keep continuity boxes.
5.set on noise option and change the default size amount because the default value is too small to resembles the ripple effect of the water need. and if the final rendering produces inappropriate size relative to the surrounding area, all you have to do is change the value.
6.apply it to the material
7. this is what it look like after apllying the material to the plane
8. notice the rendering doesnt show enough displacement for us to see the 'ripple' on the water.
the amount of displacement can be change in the Option menu on vray bar.
9. change the default value.
10. then render it again.and you can see the changes.