Monitor Vane

[excal157]

Anyone have any experience with a Monitor on a J/120 or similar boat. I have a B&G hydraulic autopilot which works great, esp with app or true wind, but I am looking for an alternative which doesn't draw as much power. Concerned about Monitor when surfing waves with big shifts in apparent wind.
Feedback would be great.

[Alchera]

I have a monitor windvane on my J120, and also have the B&G hydraulic belowdecks as well. Works pretty well in most conditions, but if you've got a the J120 surfing downwind with the spinnaker up I've found it's better to use the B&G! Even then, I switch the B&G back to compass mode rather than apparent wind, because it won't drive to true wind like some of the later models. But the Monitor will drive a spinnaker just fine so long as you don't start getting crazy with the surfing. But I would expect any windvane would have similar problems, since it's the apparent wind that's the problem.

Here's a link which shows you how I set up the monitor.

http://www.selfsteer.com/boats/view.php?boatTypeID=1186

- Mark/Alchera

[tiger beetle]

To use a Monitor windvane under surfing conditions, the game is to do two things:

1. have the boat on a point of sail such that the monitor, when it corrects for the apparent wind shift during the surf, does not push the bow through DDW and into a round down

2. reduce the monitor's sensitivity to wind shifts

1 is easy - you reach up a bit higher than you might under electric autopilot.
2 is also easy - place a downward force on the Monitor's air-paddle counterweight (such as a bungee cord run between the counterweight and the vane's structural tubes).

Adjust the tension on the bungee as needed to cause the Monitor air-paddle to return to upright quickly. I've used this extensively for running deep under spinnaker (and downwind twins) when I do want to track wind shifts. My boat is 45' IOR 2 ton lead mine, and does not so much surf as surge.

And I agree with Mark - surfing under spinnaker is not the Monitor's strong point.

- rob/beetle

[excal157]

Thanks for the info and the pictures