On Tue, 28 Jul 2009 10:34:52 -0700 (PDT), RichH
wrote:

Putting the paddlewheel on the centerline will also generate some
potential problems ..... it has to be mounted so that it cant be
destroyed by the sling of a travellift when the boat is hauled ... not
an easy thing to do.

The easiest way to manage that is to pull the paddle wheel and insert
the dummy plug before haul out. If you are really religious about
your instrument calibration it is best to pull the paddle wheels every
time you come back in from sailing. It helps to prevent growth or
slime from forming and throwing off the speed readings. When you are
trying to accurately compute true wind direction and speed it doesn't
take much knot meter error to throw the whole calculation out of
kilter.