Offset wind vane

Hello,
Is there any reason why a windvane can't be mounted offset on the transom? It seems to be not recommended but why not?
Thanks
Luke

 

You can, but you must make sure that it will function correctly while heeling. For example a servo-pendulum or auxiliary rudder design on the transom corner of a wide monohull could have its blade almost completely out of the water on one tack, and completely submerged on the other. On a cruising cat that heels maybe 2 degrees that isn't a problem at all.

 

Having the vane in the centre means it will get "clean air" equally from both sides. No reason you can not set a vane to one side or another, unless it requires more linkages to do so, which can interfere with sensitivity.
You said "vane", but Rumars pointed out the issue of the underwater part, if you was referring to that also.

 

Hi Luke, see my avatar/icon pic, it is a 10 foot dinghy, mast head cutter rigged, with an offset wind vane on one side of the rudder, starboard, pushing a separate slender rudder on the other side, through variable linkages. You had to adjust for every wind shift and direction change usually. The blue flag is the 'vane' about 1.5 square foot area useful, and under powered for the 4 inch wide ,2.5 feet deep auto steer rudder. When set up it was great in fine weather, but waves and swells and gusts overpowered its borderline abilities. The dinghy's swinging rudder can assist but that means 2 lots of water resistance. Or 2 'sticks dragging in the water' as my dad used to say. The wind vane did drag in the water on some tacks, but at those wind speeds and boat angles I was taking control anyway, and too busy to adjust it. There's probably a larger pic in my thread on here I did for the boat I called ERO, a Jack Holt Heron dinghy.

If a fixed rudder, an added on extra hinged trailing edge for auto steering would be less drag than two rudders.
So it can be done, but beware push rods and linkages and cables can interfere with other normal boating operations, like O.B. motors.
In the end, with my small sail boats, I just wanted a small tiller to gunnel mounted 12V electric tiller. Then solar.
See whats on the market that you can use, and save many many hours of mucking around. Good luck Luke.

 

Have you discovered this book? https://zaimov.eu/guides/selfsteering.pdf