: Thanks for the info. I have a favorite 9-mile course I can time
: myself with rough finish, 400 grit and maybe smoother. (If 400
: grit is the answer, it won't be hard to scuff it up again.) Do
: you sand with the direction of the boat, cross-wise, or in
: random circles?!

Good question. I do random circles- in fact I use a ROS or vibrating palm sander. The vibrating sander gives a nice matte finish and you don't see the swirl marks as much. I have seen some posts on other forums where people sanded across the hull. The idea is to create a surface that will grab a microscopic film of water that will adhere to the hull and act as a friction buffer. So that said, in theory across the hull would be better, but I still kind of like the vibrating palm sander approach as I believe it leaves a more finised look to the surface, and a more uniform matte surface.

I'm sure you've probably wet sanded a hull or a car or other surface and noticed how the sanded surface lets your hand glide, but the unsanded surface doesn't. Same principle at work.

I doubt you're going to see a whopping big difference in speed, but I do think if it is a boat you are familiar with then you will notice a difference in the feel of the boat.