The problem with windvane self steering on a small light displacement boat
is the frequent changes of boat trim when the crew moves about..

I have never tried a windvane on such a small boat but have worked with
sheet to tiller and other systems in the past. This crew movement was always
a problem..

I have read of small boat single handers doing ocean passages and they
discribed the same problem.

While it is true that a windvane should maintain the course, relative to the
wind direction, the changes boat trim is going to still cause problems.

However, on a boat with a heavy center board, where crew dispostion isn't
critical, it may be possible using some of the simpler methods that have
been devised over the years.

--
My opinion and experience. FWIW

Steve
s/v Good Intentions