Hi Greg,
I assume you are talking about spray at the bow, flying up as the boat slices through the water. You could try using just a plain particle emitter. I did it this way some years ago. I placed one emitter on either side of the boat, made them a child of the boat so they travel with it. Use a tiny sphere as the particle and you’ll have to emit a lot of them, and play with the settings to get it to look right. I think Pyrocluster would be too slow and clunky to use for this, though I may be wrong (every time I use Pyrocluster I spend too many hours trying to get it right). A regular emitter would render faster, I believe. I’m sure there’s also a Thinking Particles method, but I’m not a TP guru, unfortunately.
Jack