What you could do to get better foam is to increase emission rate and curvature threshold. The threshold doesn't range between 0 and 1 anymore, but accepts any positive value. This way you'll be able to create "hotspots" with enough foam particles. The waves' motion will then spread the foam particles and form these typical patterns.
Start with a curvature threshold around 6 or 7 and low emission rates, just to see where these hotspots will be occurring and how the foam is distributing. Once you're happy, increase emission rate and do the final simulation. You can also try to preview these areas by following this guide:
http://support.nextlimit.com/display/rf ... h+and+Foam
