I've been meaning to respond to the video you posted recently of your Dominic Tarr inspired servo-pendulum wind vane. I might as well post here because my comments kind of relate to both forms of self-steering.

I exclusively solo day sail and don't make long passages. I race on other people's boats because it is cheaper :-) I have a small fin keel boat like yours. I think I posted this same comment the last time you posted these videos:

I don't have any problem steering a course to windward under balanced sails on my boat. The first thing I did when I purchased the boat six years ago was install a WaveFront tiller clutch on my tiller. I run either end of the control line around the forward posts of my pushpit and tension the line using using a midshipman's hitch (ABOK # 1855) at either end. These line can loosen a bit while underway. Sometimes I also use a piece of bungee cord to keep some tension on the line to prevent this and take any resultant chatter out of the tiller. Otherwise, as it is a slip knot, I pull the line to re-tighten while underway. I did buy some cleats that hold better than the awning hitches but it is quicker to set up the control line using the awning hitches. I wrap the control line around the tiller so it tucks into the tiller cover when on the mooring. I don't know how anyone, especially a single-handed sailer can sail without a tiller clutch or something similar to lash the tiller in position.

Lashing the tiller or wheel is the most basic form of self-steering, as used by Joshua Slocum. For me, it works on my boat on anything forward of a beam reach and I am usually sailing in 1-2m swell and sometimes surfing with the swell. With balanced sails the boat will correct course even if it is surfing down a moderate swell. Relevant to the subject of your post above,James Everson tells the story of using a bungee cord to steer when his auto-pilot broke under passage.



As you describe in your video, the sails must be balanced and in practice that means being biased towards being under powered. A flat boat is a balanced boat. Being a solo sailer with a little boat I will reef much earlier, around 12 knots for the first, 15 knots for the second reef. Otherwise, with full main sail up, I find with my boat, I want to trim the headsail so it is fully powered but have the main sail just on the edge of luffing so that it only powers up fully to give enough weather helm to head the boat up when the headsail gets over powered. With the main sail, I position the boom with the traveller so it is nice and centred but just eas the sheet enough to induce a slight luff to allow the head sail to push the boat back away from the wind when she rounds up.

I also find that when the wind is forward of the beam, it doesn't matter hugely if I don't have the exact balance of head sail and main sail set to get the boat to perfectly track with the rudder pointing perfectly straight. I can counter a bit of weather or lee helm in the balance of the sails by setting the tiller a bit off centre.

Lashing the tiller with the wind aft of the beam is hit and miss. Sometimes the boat will track beautifully, but if it gets thrown off balance due to a lull in the wind or a wave it is less likely to self-correct.

I am yet to experiment with any sheet to tiller steering, and because of the above, I am really looking for self-steering solutions for when the wind is aft of the beam. I will try a line directly to the head sail as per your videos. I've bought some surgical rubber cord for the purpose of rigging up sheet to tiller steering. I am also keen to buy a second hand storm jib hoisted from the mooring cleat using a spare halyard I have rigged up. I understand that this can be a good approach that doesn't require the head-sail to be under-trimmed as you experienced in your video. If I find a second hand jib of 5-6m2 cheapI might grab it.

Otherwise, Dominic Tarr's servo-pendulum wind vane and your version look very interesting. This design, with the control line protruding diagonal from the stern and with the whole system able to be set off centre on the stern looks interesting because I have a stern hung rudder and I am not too keen to go mounting a massively heavy frame to the stern. It can be light-weight too because I am just day sailing after all.

What I would love to see is some sea trials of your wind vane with the wind at or even behind the aft quarter. Are you still using the wind vane? Can you update us on your thoughts since you posted this video?



By the way, I am glad you guys mentioned Dominic Tarr in this thread www.seabreeze.com.au/forums/Sailing/General/Impressed-by-the-design-and-finish-quality#2967050 I have been enjoying watching his videos and passages on his wharram cat.