I used a similar technique for years on a number of boats, most recently a 20 footer, so a lot lighter and smaller than your boat. I recently had to think about it before I remembered what I did, but I used the sheet from jib/genoa, set slightly loose, pulling on the leeward side of the tiller, against a shock cord that pulled on the windward side of the tiller. It worked, but of course it meant that the jib
was never drawing properly and it ended up mostly steering
a slightly saw tooth course.
I actually suspect that it would work better on a larger boat due to the longitudinal inertia of the vessel and the relatively greater forces available from the jib sheets
(relative, that is, to the probable tiller loads), but would make the following cautionary observations from my experiences.
Although it does work surprisingly well, I found it unpredictable in the extreme, as in, I could not predict WHEN it was going to work. For a given set of conditions, I could go for an hour or two with no corrections, then something subtle would change, often too subtle for me to detect what it was that had changed, and I would be utterly unable to re-establish self steering
control for an hour or more at a time. This was problematic as I was regularly doing journeys of 30 or 40 miles and losing the inability to self steer became a problem on even those relatively short trips.
Also, I NEVER managed to find a way to get it to work anywhere remotely off the wind
, at best a broad reach, but generally only when pointing or beating.
Eventually I gave up and purchased a raymarine
tiller pilot (which served me very well), though I regularly used the technique on the logic that the tiller pilot might go toes-up unexpectedly.
I will be trying to do the self steering
by sail thing on our current
boat, just as soon as I have the right wind conditions, but only as an addition to other more reliable options, such as windvane
setup suggested above. And of course, the electronic version, which is great when it works, but I NEVER want to depend on electrons when sailing if I can avoid it.
A separate project
is taking form in my mind to build a windvane steering unit, but I acknowledge that it would need a LOT of testing before I depended on it in any way. But I am not planning anything other than coastal hopping at the moment, and our coursemaster works well enough for that.
I suspect an advantage of an electronic autopilot
is that it will cost a lot less than a windvane? I know I would choose the windvane in preference to the electronic if I had to choose, I am only setup the way I am now as my boat came with the electronic version, and not a windvane as I would have liked.