from memory

try (im not good at this but.., ) selecting your nurbs wave.., make sure you have a lot of resolution.., say 50 by 50.., (hopefully you have already made it into a passive soft body) add turbulence from 'fields' .., add some magnitude (channel box) ., add phase direction., so the waves move in a direction., you dont need to key frame anything (although most do)..,

what else?? umm?? mess with the conserve.., now im guessing.., but if no one else will answer .., thats something you can try and you might hit on something.

i know i have forgot something important??