The rooster tail hitting you in the face is amusing first time it happens, but it soon gets annoying.
I made a small fender out of an empty Halfords oil container which had a nice front to back curve on it that looked like it would match the tyre curvature.
Mk 1 version is the purple one on the left
I shaped it to fit around the fork leg protectors and made two holes to mount it under the alloy fork brace using the two front bolts.
Mk1 was OK under about 35mph, above that it folded back so that it was vertical, the plastic was too thin.
So I made a MK2 out of a thin (1-2mm), steel sheet I had lying around. It was the backing to an old LCD monitor.
I drew around the plastic version and made it slightly longer.
Took a bit of filing to get it to fit and was thin enough to bend by hand around the tyre to give it some shape.
Finished off with a couple of coats of matt black spray paint.
Can't really say how effective it is yet as it has not rained on my daily commute for the last few months.
The road was very wet in places the other day after a heavy shower and I did not see a rooster tail.
Now I actually want it to rain so I can test it out.