That's pretty acurate for my boat. I had roots attached to the bottom of the bay before I hauled and cleaned her. But then again, I didn't have any bottom
paint at the time. Now the
paints on her she's back up above 6kts and feels great. Sails a lot better, turns on a dime, points, heels less, everything. Makes a huge difference in a boat that light. During the season I plan to clean it once a month. I like going fast.