Depends on what you mean by "finished".... if you have space for more EZ Water, you can add another thin clear layer over the exisitng finish. When the resin begins to "gel" or thicken, you can treat this to make your water waves.... for small choppy wave, you can just lay a sheet of clingwrap (sandwich wrap!) and then "lift" if off quickly... this leave lot of small "caps"... if yo want a more "rolling wave" effect, you might read some of the articles on using cotton to build white caps and to provide shape and rise to your water. Search the archives here at ARMORAMA for "water" and you will find a LOT of discussion on the subject, including photos and technicques.