My boat has a Hydrovane auxiliary-rudder self-steering gear (because servo-pendulum gears don't work so well with hydraulic steering systems).  I imagine it will work well, when the sail is properly trimmed: it worked well for the Canadian junk sloop Lorcha during her circumnavigation in the 1980s.

My boat has 516 square feet of sail on 4 and an half tons of displacement.  If over-canvassed, she will gently but firmly round-up before she sinks the gunwale: which is a good thing in a cruising boat.

But still, still: sometimes we want to push things a bit further than that..... So I am going to fit a "pinrail" under the short tiller on my Hydrovane, to counteract (just when I feel like it) weather-helm on the main rudder. I am also going to experiment with linking with servo-pendulum-style lines the auxiliary rudder with the main rudder - which should make for a very powerful in-line twin-rudder system.

In due course, I will report here as to how things work out ..... 

Hello every body! I have a junk rigged 34ft bronze centre-boarded, Allied Seabreeze ( a copy of the famous Finisterre) , schooner masted , flat Hasler sails. The boat sails a treat and I am at present in Spain after leaving  Falmouth and cruising South Britainy. I have a Hebridean Vane, one of two I built. The other is now in the Canaries after trips from UK to the Azores. My vane works extremely well but not yet tested in really bad conditions as I usually take over the helm in 35 knots and waves (I.e . tide races and overfalls in English channel!) causing havoc!! Running nervously I do not want a fan-up as boat and yard thrashes side to side. 

My boat is easy to balance so no great challenge to the gear. The Hebridean steers very accurately and has done so out of the box with no fiddling or modifications. The designers plans and advice have to be followed rigidly - but amateur DIY people beware! There were teething problems with the other gear I built for a friend's boat because advice re balancing weights etc not followed.

 Incidentally the second vane took 6 days to build full time, the first about the same spread over three weeks. Lidl sells great drill presses cheaply!  As I have an older style boat with built- in weather helm, I moved the rope attachments closer to rudder so pull side to side of vane on tiller is more than designers 15 degrees. Had I not been aware of that design fact I would not have been so satisfied.  Know your own boat traits - when there is weather helm and its rudder angles. The gear is extremely powerful so will cope well steering less tractable  boats. I have not yet formally endorsed the gear as I have not trialled it in extreme conditions when life depends on "perfection". However a wind pilot Pacific plus I installed  on another boat was not perfect and I was on occasions I was again forced to hand steer. I will gradually build confidence in the Hebridean gear, expose it to harsher conditions and report back. 

In addition to the Dijkstra Chapter, the Jester Challenge site is now hosting two chapters  from John Letcher's Self-Steering for Sailing Craft:

Len Hiley has obtained the permission of Gerard Dijkstra to reproduce a chapter on sheet to tiller self-steering from his book "Self steering for Yachts" - it can be found here.

Just to say that following my above post about linking a tiller pilot to a Hydrovane, this is what we did on Paradox prior to leaving the UK when our 1988 B & G autopilot failed. Bought a Simrad !32 which does the trick on our 39 foot boat, though not tested in rough stuff yet. The Hydrovane tiller pilot extension serves as an emergency tiller too.