On Sat, 06 Dec 2003 18:41:55 -0800, "Lloyd Sumpter"
wrote:
Last time out, I was cruising along at around 5-6 knots in 7 knots wind (45
deg. apparent), and thinking about all the "extra speed" people have promised
me: a clean bottom would get me at least an extra knot, feathering prop 1-2
knots "guaranteed!", new genny a knot or so...geez, I'd be doing over hullspeed!

============================

Absolutely! And if you buy all of the automotive gadgets that promise
to save you 20% each, youl'll have fuel overflowing from the tank as
you drive.

All I can say about propeller drag is that racing folks take it
extremely seriouly, to the point that some boats send a man overboard
before the start to put a rubber band around the folding prop. The
idea is to keep one of the blades from unfolding accidently as the
boat heels over one way or the other. We rarely did this when I was
(successfully) racing my Cal-34, but I did have the shaft marked so
that we could be sure the hinge pin in the prop was straight up and
down. That is normally enough to keep it folded up. If you have any
additional doubts about the effect of drag, try putting your hand in
the water at 5 knots with your palm facing forward. If your hand
approximates the size of a propeller blade, that is the same force
holding you back with the prop open.