Originally Posted by Omatako
Couple of things (what follows are my own opinions, YMMV):
Firstly, the modern auto pilots on a voyage use a lot less power than most people think. The computers used sense the sea state by checking for repetitive movements and if there are any they are over time, eliminated. By the time you have been at sea for a few days, all of the sea state has been removed and only course adjustment remains. We reached a stage in all our passages where the movements on the wheel were almost imperceptible and the current draw was the same.
True, if you have a boat that balances well and are a good enough sailor to be able to trim to conditions. What we see repeated in anchorages from the US to Thailand is boats with broken autopilots(motherboards in auto helm 5000, 6000 series) broken rams and hydraulics(most) broken fittings on attachments from ram to rudder post(all). All sorts of electrical issues, surrounded by NEMA interface issues(trying to make everything talk to each other) Power consumption has gone down for most, IF, and that is the big one, your sail trim and balance are in accord. Most new offshore sailors will be "over" canvased" in the belief it is faster and the
"AP" can handle it.
Secondly, auto pilots work in almost all conditions. We sailed with ours from the USA to New Zealand in widely differing conditions and the time that we spent at the wheel would be less than 1%. We only took the wheel when we went into ports/anchorages, the rest of the time the pilot did the work. A windvane will not do this - you will spend a lot more time hand steering.
True & False- Yes electric works in most conditions, until it doesn't. Then what? I still like a stint at the wheel, pretty boring to have the AP and Windvane do all the work. Most folks will not know how the boat is really sailing unless they get on the wheel. The electric AP will falsely let you think everything is fine...
Thirdly, a wind vane does not steer a straight course - it basically waddles down a zig zag course correcting itself all along the way. How many miles does that add? I don't know but it does add miles.
Somewhat true-This is the big key in the learning factor on using a wind vane. Windvane steering favors a a reduced main and more headsail (tradewind sailing, Off the wind). Also sheets need to be a looser. If your zig zagging all over you probably have to much main and are rounding up, the electric AP's are correcting for this all the time, maybe just a bit faster. The additional miles are so small as to be insignificant for me. I think we go a bit faster with sailing the vane, the sails trimmed to the wind, our Polar's suggest something in the 135 degree range anyway, which is darn near perfect in trade wind conditions.
Fourthly, a wind vane can't be made to adjust to shifting wind. If the wind shifts 10 degrees in the early evening and you're not paying attention, you could be well off course by the morning. A pilot can do both - steer a course or steer to the wind whichever you choose. You may ask why would you not want to follow the wind. Well when you're sailing off the wind (which is most of the time), an auto pilot will hold your course with very little effect on the set of the sails or boat performance.
True & False- The electric pilot will steer the course, if the wind shifts it will affect your sail trim. Why would you not be paying attention all night? Not looking at the course or trim for 12 hours? OK, trade wind sailing is easy but still, you need to be looking at things....electric or windvane.
Fifthly (is there such a word?), a vane takes up a lot of room, not only with its installation on the stern but with control lines coming into the cockpit. They're always in the way.
True & False- Boat design is a huge factor. Center cockpits are really tough for Windvane steering. However, Double enders are darn near perfect...Sugar scoop sterns, swim steps etc all make the windvane steering installation a challenge. A lot more thought needs to go into leading the lines into the cockpit... A proper set up minimizes the run and reduces friction. When not at sea, I remove them from the wheel, a 2 minute operation.
By now you're correctly of the understanding that I don't like wind vanes that much - I had an Aries on an earlier boat and even though it was at the time one of the best available, I hardly ever used it - it was too much work. I would not have another Vane even if given it for free. To add a few batteries to your electricity reserve is very little money compared to the cost of a "decent" vane.
Maybe just part of the learning curve and installation...
Just a question (and I confess to not having any background) I have had discussions with sailors in NZ regarding a wind vane made in Australia called a Fleming. They gave it rave reviews in terms of performance but I don't think it was particularly cheap or small. I don't know much about it but have you had a look at it?