I found this video showcasing the technique. I have to say, it is really impressive. Starting from 2:10min is impressive. It runs real-time on 10 years old hardware. From what I gathered so far, reducing the number of wave particles obviously lowers cost. The thing is, with such an pronounced physical effect, it would not have to be that accurate if mixed with fancy decals or something similar creating wake foam and splashes and effects to keep the eye busy.
No need to hurry with the numbers. Looking really forward to see some more results from you! (and the actual game)