To further stir up the issue, the most applicable test data I know of, is rudder testing by some British grad students (Looks to me like they had too much free time). If I remember correctly, wax made no difference. The lowest drag and best flow attachment was with a 3200 grit finish. A real 3200 grit finish would be like a brand new camera lens.

So get to work. Try a high speed buffer, white plastic rouge, and continous water mist. Oh and be sure to clean the bugs off your hull after you trailer to the water. And the sand or grass off when you get it in the water. And Oh, maybe the scum, slime, and bits of stuff while its in the water.

Or you could just wax it to make it pretty and wash it before you race.

(For those of you whose native language is not English or have a hard time with humor, the last half of this was humor. In the real world, a 3200 grit finish on a catamaran might last until the dust settled on it. I would be hard pressed to maintain an average 600 grit finish at a regatta)

Carl