Some comments on the monitor. (or any windvane)

It does not work for you in the slip (extra $$ for the extra length)

for day sails it could be useful or not? hard to tell

for a sailing voyage, of 100 miles+ not on a river, it is sooooooooooo the best money you can spend.

Lastly Scannmar is a good company with great service!

So if you rent one slip it may not be the best idea, but if you are going on a trip it would be.

For the (w32) it sticks out about one foot +/- when mounted.

And yes mine is not mounted right now as it would be only adding $$$ to my rent.

So My advice would be, to watch for one that is the right $$$$'s, and place (new or old); pick it up, and then to mount it and remove it before the marina spotted it. After which, if it is old, you could order the rebuild kit, and rebuild it in your Garage = 3 hr job? and then store it until needed.  The advice is for someone who is going to be going offshore or long distance sailing.   Also Scanmar can help with the mounting hardware as they have designs for the back of most boats.

Mounting after the first time takes about 1 to 3 hrs depending how many nuts you drop.

The two great +'s for the monitor is that it uses no battery power, and it is very reliable in almost all sea states, if you replace the lines every 10 years from the sun or 20K miles of hard sailing, it is great.  Your mileage may vary.

The ones on e-bay may be from guys who are now only doing day sails? in any case I do recommend the design, but you do have to inspect the hardware for yourself.

One thought (a bunch of westsail guys did a group buy on the capehorn sometime back) It would be great if you could somehow find out how they all felt about it, and its operation after 3Years+. 

As for USED Monitors, I had one, a few years back, and Scanmar did not want to repair it. They have beefed up their latest version and it is worth the money if one really prefers one.

Lots of moving parts to a Monitor.  Cape Horn is a lot simpler in design and just as effective.  The Cape Horn also keeps the overall length of the W32 at 40 feet.

a bit more

Very Old monitors did not have a ss arch behind the bottom legs and they also had some no longer produce parts in them. Without the bar around the back bottom You could get some cracking as it needs the support there.

Things that needing inspection 

The LINES for ware. = replaceable;    CRACKS, if it was backed in to a dock or other;   The PLASTIC BUSHINGS(for the turntable) = Replaceable:  The CHAIN for rust or ware = replaceable: The LITTLE SWIVEL PINS and CLIPS on the rod going up and down from the paddle = replaceable: The CONNECTION to the blade (the one in the water) = May be replaceable ? welded ? other?:  and general overall once over lines, pulleys ,etc.   But it is not that tough.

One thing I have not heard, is how does the Cape horn perform?

It concerns me that everyone is talking about how it mounts, looks, does not stick out, simple, etc. And not much on performance in (X conditions) I believe they may be ok but no one is talking  about performance in (high wind, light wind, down wind, or ?)  The only one I have known about, had some issues with the paddle being to small, but I did not ever here if it had got fixed.  There were allot of them bought for the group buy so there should be data!

Lastly: for the auto pilot (yes you can with a dummy paddle) but I only use the autopilot under power, so I am not sure you gain much unless you bought the super cheap autopilot for a 18 footer, in which case yes the vane would help improve its' power. The trim tab could as well but some design work would have to be done. The more important thing is, the new ones can work as an emergency rudder which I would hope is never required.

As for the three conditions the monitor has not work well for me

1. Dead calm = not a thing until about 1/2 a knot with the big paddle and one kt reg  (On the other hand the boat won't move either if it does the vane will work.) also motoring in dead calm or faster than the wind (down wind) will not work.

2. 25 ft+ Breaking seas for which the boat is mostly under water most of the time (I used it, but had issues of changing wind speeds an directions,  between the bottoms and the crests of the waves) the waves when big and close, have local wind patterns;  just think about the wind pattern around buildings.  Not sure an auto pilot would have worked as the loads and seas needed to be piloted through so as not to come abeam to a big breaker.  

3. in the slip it cost more money to have it mounted

a. On dead down wind I recommend the big paddle as the wind can be very light, and if you are going with a current you may get close to wind speed but 99% of the time it seams the big paddle works fine.

b. performance (my opinion) is some where between 103% to 90% of a good helmsperson the bigger the waves the lower the performance, the Westsail will pushoff from the waves and the vane (or autopilot) will not anticipate this, so speed will be lost.  This is the one area that has yet to be addressed buy the wind vane producers (pitch input, helping  the steering). 

WESTSAIL   please look at item #3