Almost nothing is as important on a cruising boat as self steering. Recently Alison and I have been sailing on Sydney Harbour, and have had to hand steer. This is a shock to the system, because we have probably steered more this year than we did on the whole trip from the States.

When we first bought our boat it came with a Fleming Major 103 windvane, probably about thirty years old. Its name is ‘Flem’. It is heavy but strong, with a full four-point mounted frame made of stainless tube. It uses grease and nylon bushes to reduce friction, and has a big stainless oar in the water. It the Florida Keys we picked up a lobster pot with it and bent the shaft. We got it straightened but it still has a twist in it, so using it downwind is a black art. Despite this it steered us across the Pacific in light winds and heavy with only the occasional hiccup.
We also bought an Autohelm 3000 before we left. It is very disappointing that people make boat gear that is not waterproof. The first time we had a wave break into the cockpit the controller got water in it, and eventually stopped working altogether. I bought another used and tried again, but this time the motor unit got progressively weaker until it stopped working too. I now have a Navico tiller pilot to hook up to the windvane, but I haven’t done a good permanent job of it so it doesn’t get much use yet. It got pretty wet and still works, so fingers crossed.

You can probably guess that I like windvanes and don’t like autopilots. I dislike the tyranny of the wheel even more, so we carry both. We only use our autopilot for in-harbour sailing, and motoring. As far as I know there are only a few situations where an autopilot is better: For catamarans and planing monos the apparent wind swings around when they accelerate, making it hard for the vane to stop the boat from swinging across the waves. Obviously a vane needs at least 2-3 knots of apparent wind to function, and more is better.
The disadvantages of autopilots are many. They are expensive and complex, and the cheaper ones are not intended for protracted use. They use precious power. They break, so you need some sort of redundant backup for them. If the wind changes and you are not using an apparent wind sensor (most don’t) the sails are not trimmed any more. Of course there is something nice about sitting in a pilothouse steering by computer...
The vane, on the other hand, steers day in, day out, using no power apart from the wind and water. They keep your boat at a constant angle to the wind so that it is sailing as efficiently as when you trimmed them. You just need to have a compass below to keep an eye on the heading. They can be a pain to get set up properly, especially in light downwind conditions. They are expensive too, but a good one will last a very long time. Ours uses farm equipment level technology that any machine shop can repair without having to send away for parts. It is heavy and on the end of the boat, at the very worst place.
For me the decider is performance in heavy weather. The harder it blows the better the vane works. Coupled with our heavy boat with its full keel there is no need to steer in heavy conditions. We can just curl up in the foetal position below and pop up every fifteen minutes or so to check for ships. I have even been known to turn on the radar for a couple of minutes to keep from getting wet. It always amazed me to be surfing down twenty foot waves and watch Flem faultlessly hold our line down the face. I had the emergency tiller re-made in stainless in Noumea, but they made it too light. We normally connect the vane lines to this tiller to steer the boat. When I hit the first set of bad weather on the way to Bundaberg the vane was so strong that it twisted the tiller like a pretzel. I hooked the lines onto the wheel adaptor for the autopilot and kept going.
Now we have some time on our hands it is time to get Flem re-built, or even replaced with a new Fleming model. The bushings are loose, the twist is still there, and the oar blade is rusting a bit along the welds. I want a proper wheel adaptor for the lines to hook onto. It won’t be cheap, but I know that when I get the bill I won’t begrudge it. The gratitude I feel towards the contraption on the back of True Blue is hard to express. Then Flem will be ready for another trip, this time around the world.

How do windvanes work?

The servo-pendulum windvane is a pretty mysterious looking beast, but it is actually pretty simple.
They have a sail, normally made of wood or plastic, that is hinged at the bottom and kept upright by a counterweight. You set this to point straight into the wind.
When the boat turns, eg to port, the sail is pushed on one side by the wind and flops over.
This uses gears to twist an oar that hangs down into the water, which has a pivot so that it can swing from side to side. Twisting the oar exposes one of its sides to the water flow, which swings it to the side with great force.
The oar is tied to the boat’s tiller so that when the oar moves it steers the boat back the right way. Once the boat is back on course the sail is upright again, the oar goes back to centre, and the tiller steers straight too. And you slept through the whole thing!
In a good breeze all this is in equilibrium, and the corrections are very small. Add some big waves, though, and it has more work to do. Fortunately with the waves there is more wind and the boat is going faster, so the vane has more power to work with.

Tips for windvane sailing.

1. Balance the boat! Regardless of the quality of the windvane, the corrections it makes at the tiller or wheel are not very big. You need to balance the sails so that there is not much weather or lee helm. Roller furling is good for this because it lets you make small adjustments to the size of the genoa.
2. Chill out. If you are 10-20 degrees off the rhumb line it doesn’t make much difference at all to your time on passage. Let the boat sail where it is happy, and it will probably go faster too. Use your knowledge of the weather to pick the side of the course to err towards, so that the sailing tomorrow will be easier or faster.
3. Play with the line tension. Some setups like slack lines, others have to be taut. I think it depends on how responsive the vane is in relation to the sensitivity of the steering. On our boat I use a bit of slack in the lines, and set it up so that the vane is steering against a slight weather helm. The other line is there to stop the boat running away to leeward if a wave twists the stern through the point where lee helm sets in. Quite often it is not doing anything at all.
4. Consider all your windage. For us to run wing and wing downwind we need to put the mizzen boom to the opposite side to the main, even if the sail is down and the sail cover on.
5. Use a preventer! We ran wing and wing most of the time downwind, with the main a bit by-the-lee. The main ended up inside out more times than I care to remember. We never managed to eliminate accidental gybes, so we always had a tight preventer on going downwind. Get the main right out, as far as it will go.
6. Move the centre of effort of the sails forward when sailing downwind. The easiest downwind sailing we did was when we had a genoa out one side and the drifter out the other. We only did this during the day because we only had one pole and it was too hard to keep the loose sail filled in the dark. Next time we’ll have twin poles.
7. Keep the vane in the clear. I just know if I get rid of the outboard motors on the pushpit, roll up the bimini and raise the mizzen boom a bit, the vane will be so much happier. I will, next trip, I promise.

Emergency steering.

OK, a killer whale just jumped up and ate your windvane. What next?
An Allied Seawind called Apogee was the first fibreglass boat to sail around the world, and it made it without a windvane. A long keel helps a boat track straight. Alan Eddy used a combination of techniques depending on the point of sail to get the boat to self steer, and he described them in his booklet So You Want to Sail Around the World.
Going upwind, self steering is normally easy. You just sheet the genoa in tight and let the main out a bit. As long as you have enough main (or mizzen) to overpower the lee helm from the genny the boat will steer itself.
On a reach it is much the same, the sails are just further out.
On a run the boat must be very well balanced. If you don’t have a spinnaker or twin jibs it is much harder, and it will probably be necessary to rig up some type of sheet steering to the tiller to get it to work. It might just be easier to broad reach under genny, and use the weather patterns to pick the best tack while you tack downwind.