Monitor Windvan

[Mark]

Hi Mateys,
I have purchased a Monitor Windvane at the Strictly Sail Pacific boat show in Oakland. I'm going to install it myself. The instructions indicate the height of the paddle should be six inches above the waterline, when the boat is at rest and loaded for cruising. As my boat is not loaded and sadly cruising is three years away, does anyone have an opinion on how much the boat will settle when we are ready to shove off? I know this is dependent on how much stuff we bring, but since I'm leaving my anvil collection at home, perhaps just a range?

Thanks, Mark

[mimoza]

I just spit balled a few numbers, and the result was such a round number that I had to share it.
LWL ~25'
BWL ~10' (beam)
area of a circle is pi*r**2 or pi/4 * diameter**2 or roughly 3/4 of the containing square.
So let's say the ellipsoidal footprint at the waterline is roughly 3/4 of the containing rectangle

LWL * BWL * 3/4 = 187.5 sq ft
divide by 12 to find added displacement per inch = 15.625 cu ft
water weighs about 64 lbs/ cu ft, so it will take 1000 lbs to load the boat down an inch. If you add 3000 lbs of gear, etc. your waterline will rise about 3".

Like I said, it was spit balling. You can probably do better with a hull diagram, but it's something.

[Mark]

Cap'r Bri,
Thank you so much for that. I was wondering how to do the math, and this is a great place to start. Sorry I didn't get back to you sooner. Damn work gets in the way.

Mark

[jonneely]

We are fully loaded cruising and we have found that our indented waterline mark is pretty much right on. Prism sits on her lines with full tanks. We also have a 100lb Flemming Major vane on the back along with panels, radar, propane and all sorts of other things. Not sure if all years have the same water line mark but ours seem right. If you are planning on not leaving for a couple more years I would urge you to wait on installing your vane, I know with ours it adds another 3' to our LOA with the rudder swung up. If you are already in an oversized slip go for it, but I know when we installed our vane in WA that same week the harbor master remeasured us.

[edelweiss]

Just for fun I thought I would add the following:

When under way, the waterline is different then it is at dockside with calm water. Waterline comes up a little. ( about 6 inches )

Since I use my Hydrovane most effectively while under way rather at dockside you might consider this when installing.

[Mark]

Hi All,
Thanks for all of your responses. We are in a 40 foot berth already, due to the bowsprit, so I'm hoping the additional length won't cause any changes; we are already overcharged as it is. The windvane had its maiden voyage last week and things went pretty well. A bit of a learning curve, but I hope to dial it in with long cruises...someday soon. Thanks again for your input.

m

[edelweiss]

I should have added that the most of the most of the monitor nests nicely with in the pushpit but the blade folded up will stick out adding another foot to your overall length affecting your slip fee. Ideally you should attempt to get the blade as deep as you can while underway so a much water is hitting it. Waves and boat motion will bring it up and down of course.

There are pictures on the net and the monitor website that show hcs for a rough idea.

There are also several variations to routing the control lines back to the wheel. Ours included some fairleads right thru the hull with some blocks to re direct it up to the wheel. All located at the aft end of the cockpit floor which seemed to be OK as it was awkward to stand in the cockpit floor behind the wheel anyway. I dont have ant picture and we have since switched to a Hydrovane with no lines. Monitor is the most widely known so there are many hcs with them. Others may have photos of their installation.