Larry and Lin Pardey’s homemade vane worked on the trim-tab principle. Their boats were unique though, in that they both had aft boomkins which informed the design to a large extent. However, if it was good enough for the legends, then there must be some merit in the design. It’s worth looking in to!
Modern, commercial designs mostly lean toward the servo-pendulum concept, mainly due to the force-magnification inherent in the design. The only real stumbling block to choosing one is the almost universally unaffordable prices. We’re looking in the region of R35 to 40k. That’s a lot of money. There are cheaper options like MrVee (made out of plastic) at R15k but how long will it stand up to the rigors of offshore voyaging?
DrakeParagon doesn’t seem to have a ‘vane and relies solely on an electric autopilot. Looking at svParagon though, he has made a SUBSTANTIAL outlay on the electrics, so much so that he could just as well have installed a windvane.
‘Blue currently has nowhere near enough battery (and charging) capacity to do a multi’-day voyage under autopilot while still running nav-lights and interior electrics. I even have my doubts as to whether ‘Enry Autohelm (an ST1000 tiller pilot) is actually up to the task? ‘Blue’s captain is also terminally short of funds, so the temptation to cut costs by going for a “cheap-and -nasty” solution is always there.
But ultimately, considering the utility one gains from what is essentially another, tireless helmsman, perhaps cost-cutting in this specific area isn’t a wise decision!?
Anyway, we’re getting way, way ahead of ourselves here. There’s plenty more to be done, plenty more, before considering the fitment of a windvane.
InlandSailing once had some thoughts on the topic.