Windvane vs. Mizzen boom

[w00dy]

Does anybody here have experience in sailing a split-rig boat with a windvane? How did you resolve the issues related to contact between the vane and the mizzen boom and airflow interference?

I'm considering a ketch that currently has a windvane installed. The owner reports that he must "simply" lower the vane (?) during each tack/ gybe and reset anew.
Still, I am concerned about the need to turn suddenly and the ensuing choice between damage between one important system or some other catastrophe.

I have been reading around the web and have found references to several solutions/ideas, each of which seems to have some downside. (nothing's prefect, right?) For instance:

- some sort of breakaway system, such as a sheer pin etc.  Wouldn't this make the whole system weaker/ prone to constant breakage?
- raising the mizzen boom permanently. This would deform the mizzen sail and could affect sailing characteristics, though how much???
-running a topping lift to the cockpit, to be used when tacking. One more line to pull on a cutter rigged ketch...
-attaching a fore-guy to the mizzen to prevent unintentional tacking/gybing. Once again, what about the need to quickly turn/maneuver.
-not using the mizzen at all. Say goodbye to that balanced tiller.
-letting the boom have it's way with the windvane....yeah....probably not.

Anyway, I suppose if you're on a tack long enough to need a windvane, the occasional extra routine of _whatever_ wouldn't be that difficult.  I get the feeling this is one of those "there is no right answer" kind of questions, where every solution involves some compromise. Just looking for some additional insight, your opinions, ideas, and experience, whatever they may be, I want to hear about it.

Unless you're about to say, "well, have you heard about sheet-to-tiller...."  ;D

[rorik]

This link below takes you to a list of boats that Cape Horn has put their wind vane on. Scroll down to the Cheoy Lee 41 ketch, click and there are pictures that may help.

http://www.capehorn.com/sections/liste/liste2006.htm

EDIT:
Now that I've posted this and then re-read you your post..... it might not help at all....
When you say he has to lower the vane, does he mean that he pushes the horizontally rotating vane to horizontal until the mizzen has cleared it, or does he mean that he literally has to do a quick disassemble/re-assemble in order to tack?
If the latter, I would suggest that the wind vane is not suited to the boat or that it was improperly installed.
My understanding, and I'll know a lot more in a few months, is that the vane needs clear air. Any sail or dodger should not block the vanes apparent wind. But the bottom of the vane only needs to be a few inches from the top of a dodger to be in clear air, or the top of the vane a few inches beneath the bottom of a sail.

EDIT - PART DEUX:
http://www.boatbanter.com/showthread.php?t=71803

[s/v Faith]

Ok, this is going to sound crazy....

(any post that starts like that probably ought to end like that too)....

What if you experimented with some really light weight vanes made out of something sacrificial?

For example, those poly/cardboard yard signs like politicians put everywhere?

The idea being that if you had to tack / jibe in an emergency (like MOB) the vane would be light enough to fold/get distorted to absorb the energy.

[rorik]

The vane makers (wasn't that a movie with Burt Lancaster?) usually have a light air van and a heavy air vane so I think if you made a really light, sacrificial vane, it would affect the vanes performance.

[okawbow]

I used a home made windvane on our Cheoy Lee 31 ketch, this spring for about 1000 miles of blue water. I just let the boom push the vane out of the way when tacking.  I didn't tack very often with the vane on though. I also lifted the boom by hand whenever I could. It was inconvienient sometimes, but I never damaged the vane.

Your set up may not allow you to do that, however. I set our boom as high as I could, and the windvane as low as practicle.

We ended up taking the vane off when doing coastal hops. It just didn't work that well in light air, and I had a problem with a set screw that wouldn't go away. Our TP 10 tiller pilot always did a good job though.

[Jim_ME]

Looking at the Cheoy Lee Offshore 41 photos on the cape horn site, the boom shown ends far forward of the wind vane (and the wind generator post).

However, the sample photos for the Allied Seawind II show a ketch with mizzen boom extending above the stern and a shorter windvane which is [appears to be] below its swing area.

[rorik]

Cape Horn has 4 models that can each be custom fit (to a certain point) to the boat in question. The Jean du Sud is the integrated model, the Varuna is better suited for boats with outboard rudders, etc.... That flexibility, among many other things, is why I chose one for Mathilda.
Both boats have the Jean du Sud model but they shortened the vane post on the Allied so it just cleared the house top on the bottom and the boom on the top to get clear air.

[Cruise]

 My Allied Seawind is also a cutter-rigged ketch and has an Aries windvane on her. I have not had a chance to give the Aries a good workout yet -- hopefully this summer on a cruise to Maine, and then I will be able to share some firsthand knowledge with y'all.
The manual for the Aries addresses the subject. Here is what it says:
 " Mizzens
Very few mizzen booms are high enough to clear the plywood vane (1600mm above mounting tubes). I feel the worst and only problem is when closehauled with the mizzen boom sheeted in hard to centerline. Under these conditions the vane is limited in its travel by hitting the boom. The remedy is to set the vane up to the weatherside using only half of its movements which is quite acceptable as most yachts are virtually self steering when on the wind. Slight easing of the mizzen sheets helps a great deal and you can also pivot the vane aft in its clamp to 45 degrees off vertical without any ill effect which will probably clear under the boom anyway.
The vane can be pushed down horizontal in its clamp which is very useful when maneuvering or gybing or tacking. No matter what you do to the plywood vane you cannot break its mounting casting, connecting linkage or any other part of the gear. You can easily make your own vane from 6mm plywood.
Experience has shown that the backwinding effects from the mizzen on to the vane when closehauled are unnoticeable (the yacht's inherent directional stability no doubt help here)."
Hope that helps.

[w00dy]

I will likely get some more experience with this issue later this spring, if all goes well. I will elucidate further sometime soon.

In the meantime, thanks for your input and honest opinions. Have a grog on me :)