Down wind sailing with monitor windvane

[RDW]

I am doing a lot of downwind sailing. I am doing the World Arc. I have used my Monitor windvane a moderate amount upwind with good success. I am have trouble downwind. I am rereading the Monitor instructions. I would love to have some advice from expert experienced sailors. Monitor instructions basically say it is all sail trim but give me more info on trimming wing on wing with a poled jib for the windvane to work better. We have been sailing about 20 degrees off dead downwind.
Our next try might be two head sails poled out on each side. I have heard the vane does well with this.
I need to get better because I do not want to over work my autopilot and I have a lot of downwind to do.
If interested go to A Journey Round the Globe – A Journey Round the Globe
RDW

[roverhi]

Do you have the light air plastic wind vane for the Monitor?? The problem with downwind is the true wind is reduced by the speed of your boat. Sailng DDW in ten knots of wind at 5 knots boat speed and wind vane is only seeing 5 knotsof wind across it which may not be enough for it to react properly. If you are surfing, you can get a 180 dgree reversal in the relative wind. A larger sensing vane will help as will making sure you have minumum friction in the steering line blocks. Another problem is following seas slew the stern of the boat around requireing a lot more steering input than other points of sail. If you have a tiller, you could move the steering line aft on the tiller to increase it's sensitivity to input and range of motion. Reduces force applied to rudder but a balanced spade rudder takes relatively little force so that might work. It would be a major job with a wheel to do the same thing as you'd have to increase the size of the drum on the wheel.

Failing that and you want the self steering to work either head up to a broad reach or where ever the wind vane can reliably sense the wind. If you can't make the vane with a larger vane, etc might consider hooking tiller pilot to the vane. Miniumum power draw and the tiller pilots are relatively cheap.

[Celestialsailor]

Another way is to buy a cheap tiller pilot to replace the air vane and use the pilots magnetic compass to keep you on course. otherwise steer 10 degrees of the wind.

[robert sailor]

If your sailing downwind in light airs you can do a couple of things, use a larger lighter wind vane usually made from corrugated plastic, attaching a light plastic or nylon ribbon about 3 feet long to the top back edge of the vane helps and finally allow some slack in your steering lines that attach to tiller or wheel. Twin headsails do help, for sure because the main adds helm but it will probably add some roll. All vanes steer better as the boat speed increases because they are getting the force from the servo oar but playing with the changes I suggest should help you steer in the lighter stuff.

[AiniA]

We did not have any problems downwind with our Monitor. I suspect our boat is heavier than yours although similar LOA. Having as much sail area forward as possible helps, although we were able to go wing and wing as well. We did use the larger wind vane, basically all the time, even when the winds got up and it would have been dicey to make the change. The vane is incredibly strong - I think it is made of corrugated polycarbonate.

[captmikem]

A lot of people sailing down wind do not carry enough sail, the Monitor likes boat speed especially downwind.

A 130 on the pole in 25 kts downwind is not too much sail.

That said, dead down wind wing and wing it may help to put a single reef in the main if she is wanting to round up. and make sure the boom is out as far as possible, a preventer led forward and a vang to the toe rail socks it in tight and keeps it from chafing too much on the spreaders.

And as stated above, the larger light vane is a big help.

Have a good trip,

M

[barnakiel]

Dead downwind is the most unstable directionally and the most rolly life onboard. Sail long broad reach tacks. This improves wind speed over the vane, directional stability and comfort onboard.

Otherwise as others said get the biggest vane wing.

b.

[senormechanico]

If you haven't already, minimize any steering friction you can find.
This includes all blocks in both boat and wind vane lines.
It goes without saying that you need a balanced sail plan.
With our previous boat (Lord Nelson 35), the Monitor would operate the boat's rudder after about 5 knots apparent.

The Monitor was able to keep course DDW with just our asymmetrical spinnaker with no mainsail in less than 3 knots of wind .
With that small amount of wind the rudder wouldn't move off center, but the Monitor's oar was enough to keep the boat on course.
The reason it works DDW is because of the forward center of effort provided by headsail only .

[phydeaux]

The consensus is largely correct regarding downwind sailing with the vane. The simplest way to put it is "apparent wind". Sailing deep with two poles can work just fine on long reaches, and dead down, but you will need enough apparent wind acting on the vane to make it work properly. We test a lot of various combinations of spinnaker and whisker poles in varying conditions here at Forespar, since we make a lot of poles.

[joel383]

Originally Posted by phydeaux

The consensus is largely correct regarding downwind sailing with the vane. The simplest way to put it is "apparent wind". Sailing deep with two poles can work just fine on long reaches, and dead down, but you will need enough apparent wind acting on the vane to make it work properly. We test a lot of various combinations of spinnaker and whisker poles in varying conditions here at Forespar, since we make a lot of poles.

So, compromise with less boat speed, move sail foreword= more vane control?

[phydeaux]

The result may be less boat speed (but often better VMG), but the original subject was effective wind vane steering. Yes, you need enough apparent wind over the vane's surface(s) to make it work. Sailing deep in larger swells can be more than a little varsity, but doing so with a vane is situational. I generally won't if the trough is blanketing sails....

[Sailormantx]

Try sheeting your jib centerline, it acts like an air rudder forward and helps the Monitor a lot when going downwind. It is generally best to avoid dead downwind unless steering by hand as it is too easy to get the wind on the wrong side.

[Paul Elliott]

Make sure that you have unobstructed airflow over the windvane. A bimini, stuff hanging on the stern railing, a big navpod in front of the wheel -- anything like this can screw up the airflow and make course-holding difficult. You may find that some headings work well, but others are quite squirrely. This is true for any point of sail, but downwind is particularly difficult given the low apparent wind.

[RDW]

Paul, is this a general statement or would stuff ahead {down wind} of the windvane sailing downwind or dead down wind affect how the wind vane would perform?
rdw

[Suijin]

Every boat seems to react differently with the Monitor. I've sailed on quite a few, and each one required it's own trim and adjustment methodology. Depends on hull speed, sail balancing, wind vane size etc. Also, your steering ratio can be an issue. The vane does best on wheels that are three turns lock to lock, it seems.

Someone mentioned friction. That can be really important, and you should check that the lines to the wheel adapter have as straight runs as possible. Can make a big difference.

If you're doing the ARC you'll be doing a lot of trade wind sailing, where the Monitor really comes into it's own. Get it sorted and you can sail 2000 miles at a go without ever touching the helm.