On Sun, 08 Jul 2007 07:04:51 -0700, Udo wrote:

It seems that water would be turbulated. Would that not generate more
drag? Is there an other reason why the bottom is textured,
like preventing laminar transition drag?

Most successful sailboat racers are fanatical about maintaining a
mirror smooth surface on the bottom, especially the leading edge of
the keel and rudder where most of the lift is generated.

The usual drill is to wet sand the bottom paint first with 220 grit
followed by 400. We used to start with an X shaped sanding pattern
using rubber fairing blocks, finishing with longitudinal strokes
parallel to the water flow.