In "Robert or Karen Swarts" writes:

Anyone care to discuss the relative reliability of
autopilots(electric/electronic) vs wind vanes for sail boats? Are wind vanes
still widely used?

The electric autopilots and windvanes are a totally different kettle of
fish. Both steer the boat, but their best areaof application is a bit
different. A medium range autopilot can be bought by some 300 dollars or
Euros and a windvane will cost you about ten times as much. If you are a
coastal sailor and want to have the gear to relieve you from the helm
for some time, the autopilot is sufficient if the conditions are not
extreme. If you want to cross the ocean then I will advice you to buy a
good windvane. If you have a servo-pendulum windvane you will find out
that the harder it blows the better you trust it. Especially on a run in
big vaves and oskillating winds the windvane is superior to the
autopilot, unless you buy an autopilot to match the price of the
windvane.

The important difference is that the servo pendulum vindvane gets the
power to steer from the boat speed throught the water, the vane only
turns the angle of the servo blade and the faster you go, the stronger
is the steering movement. Most of the autopilots have a "single speed"
electric motor that is on or off and the speed of the steering action is
not related to the boat speed. That makes the feedback and the damping
of the movement very difficult.

There is a strong competition between the autopilot manufacturers and as
they are more or less related to some big electronic companies they can
invest lots of money to advertising and because most of the sailors are
coastal sailors they sell a lot of the equipment. On the other hand the
Windvane business is a handiceaft and small business, for example the
market leader German Windpilot is owned and run by one man. He has some
sophisticated computer steered engineering machinery, but the pilots are
done one by one and assembled by hand and they are sold more by from
"mouth to mouth" and "satisfied custores is the best add" principle you
do not hear about them if you do not move in the right circles.

Most people who have a windvane have an electronic pilot as well. They
use it while shorthanded hoistin sails or comin or leaving ports, but as
soon as they are at large, they will put the windvane on. The windvane
does not use any electricity and is absolutely silent. The autopilots
try to give you the impression that their power consuption is some 0.7
Amperes, but if you end up running in difficult conditions then they
will use some 4-6 Amperes, enough to dry many batteries used on todays
small craft.

I believe that the autopilot are sold in bigger quantities perhas some
ratio 100:1 or even 1000:1, but if you take some off shore sailors then
the ratio is 1:1 because they have both.

- Lauri Tarkkonen