I have logged quite few ocean miles with a windvane
self steerer on Crowther 33' Buccaneer trip a few years ago. It was a simple horizontal pivot vane with thin cord and some small chain to attach it to a pin on the tiller. The rudder
was a balanced spade. The van was mounter on the stern of the main hull
with the pivot about at the same height as the boom. The design was from the NZer Bob Belcher, and it cost me some spares and scrap plywood
The vane worked exceptionally well to windward and around to a broad reach in wind speeds from 5 to 35kts and boat speeds of 3 to 18 kts. Over 18 on a reach you really needed to be on the tiller to make the best of the 20+ bursts down waves.
The vane also worked well downwind....it was my only helmsman from Tonga
to Noumea to Coffs Harbour NSW. But you had to have at least 1 reef in the mainsail
(to be frank for much of those passages I was happy with just the headsail and to jog along between 5 and 8kts) and accept that the boat would make a very pretty 3 wakes in a wavy S pattern with the course varying +/-15 to 20 degrees (who cares if the sailing is downwind and it is bare tops and shorts weather
day and night?). The only problem I had was in VERY steep waves along the NSW coast downwind with the main hoisted. We would surf a wave, the boat would jibe then accelerate on a broach/reach....the only time I have been worried about capsize
. Problem fixed by dropping the main.
I now have an 11m Simpson cat with wheel steering
with an Surgeon tiller pilot driving a pin on the wheel
(1 turn lock to lock). The wheel is attached to string (spectra braid if you are a wanker) which via blocks go to a tiller bar on each rudder post, providing a pull-pull system. So far this has worked great, though it has difficulty in following seas as much as the old wind vane
. I am currently trying to figure out how to install the same windvane
I had on the Buc33, but driving the wheel via a telefax cable also to the same pin on the wheel. I don't trust tillerpilot.
In all of this I have assumed the boat is easily steered....not the white-nuckled feats of strength I have experienced on keel
boat tillers and wheels, but the two fingered touches needed on a good multi. I can highly recommend Belcher's book on self steering gear