Windvanes 101Crash Course in Selfsteering Systems
To Have or Not to Have: Autopilot or Vane Gear?
Obviously, you have to decide whether you want or need self-steering at all, before making the choice between autopilot or vane gear.
In our experience a self-steering gear is one of the most enjoyable devices you can have, even on small daysailors. Steering is only really fun for a fairly short period and quickly develops into drudgery. Self-steering frees you to walk about the boat, navigate, cook and eat, rest and get out of the weather, sail short-handed and many other similar advantages.
On a passagemaking cruising boat, traveling day and night, self steering makes the total difference between enjoyable sailing and a constant battle between fatigue and boredom. It does not matter if the crew is large. Without self-steering someone has to sit at the helm at night, watching the compass with red and windblown eyes. This may briefly have its reward in heroic feelings about oneself, but not for days on end. To the experienced cruising person self-steering is as important as his charts and he or she will never leave port without it.
The safety aspect should also be considered. A well rested crew is less likely to make bad decisions. Tired crew, exhausted by lack of sleep and exposure to the elements, do not perform at the best and may not think clearly in an emergency.
As stated, autopilots seem to be a more acceptable concept than windvane gears. There are several reasons for this, but the main one is probably that autopilots are more readily understandable than windvanes.
We all know what a compass is. We are all familiar with electric motors and easily understand that one can be used to turn a rudder. As for the "program" part of the auto pilot, we live with button controls every day. As long as they produce the desired result most of us are perfectly happy not knowing exactly how the result came about.
Another aspect which makes the autopilot readily acceptable is that it does not require any perceivable changes in the looks of a boat and few or no holes through the hull; and the proud new boat owner often feels as though undergoing amputation when a drill bit sinks into his boat. As the autopilot is not externally mounted on the hull, and if looks are more important than function this will be a consideration. However, a boat with a windvane on the stern will always attract attention and knowledgable saiors will know that the boat has done or will do serious blue water cruising. Those who have voyaged with a windvane say "The more it blows the better it looks".
The largest single draw back of the electronic autopilot is that it requires electricity to operate. This is unimportant on a powerboat, where the engine is always running and charging when the pilot is engaged. A sailboat, however, does the majority of its traveling under sail. Keeping the electricity flowing can be a nuisance or even a major problem. The situation is aggravated by the fact that there are so many other devices on a cruising sailboat making their demands for electricity: radios, instruments, refrigeration and lights. A lot of expensive fuel and noisy engine time will have to be allocated to keeping the autopilot fed with current. Expensive and heavy batteries will have to be added as well as a number of generating systems with accompanying spare parts. If the boat should lose its ability to generate electricity it will also lose its self-steering, if the steering is an autopilot.
Salt, humidity and water mix very unfavorably with electronics. It is not unfair to say that the long term reliability of autopilots suitable for cruising sailboats is considerably below that of a decent vane gear. The condition is aggravated by the fact that the average sailor is unable to repair his autopilot after it has broken down in the middle of the ocean. It can even be a considerable problem to get it repaired ashore in remote places without the proper expertise and parts.
We have already mentioned that the principle of steering by the apparent wind used in vane gears is more suitable to a yacht traveling under sail. The boat will travel more efficiently with optimum sail trim and should not gybe in a windshift.
A good vane gear will steer better the harder it blows and the faster the boat moves. Hard wind produces truer signals from the air vane and the greater speed of the boat makes the servo device more powerful.
The opposite is true for an autopilot, large seas and heavy weather force the pilot to work very hard with lots of current draw. Our feeling is that a good vane gear performs better and more reliably under average open ocean cruising conditions and goes on to perform dramatically better and safer in hard weather. Tony Gooch, who completed his non-stop circumnavigation in 2003, wrote an article in the January 2004 issue of Cruising World in which he compared the efficiency of mechanical windvane and electronic coursekeeping systems. Read his surprising results here, and look up pictures of "Taonui" in our Boats & Photos section. The article is in PDF format. Download the article.
On the other hand the vane gear is completely useless in a calm and not particularly efficient in very light airs and slow speeds (under 1 to 2 knots). For powering the autopilot is definitely the right solution, even if a vane gear can be used when there is a reasonable wind blowing to give the air vane something to work with. A comprehensive discussion about both types of selfsteering can be found in our Windvane vs. Autopilot section.
If you are a daysailor only, if you are looking for self-steering primarily when powering, if your sailing is in flat waters and close to repair facilities, if your self-steering is a convenience to be used now and then rather than a necessity, if you can provide electricity on board and do not mind doing so, you should have an autopilot.
If you stick your nose into open waters, if you sail in an area which normally has a lot of wind, if you make passages under sail, even if only a couple of hours long, if you want self-steering primarily when you are sailing, if you are concerned about conserving electricity and fuel and the reliability of electronics, you should have a vane gear.
If you are going to voyage on a sailboat making longer ocean passages you must have a vane gear. The vane will steer you anytime you are doing any reasonable sailing, which is hopefully most of the time, without employing your batteries. On the ocean cruising sailboat the vane gear should be the primary choice for self-steering and this is where you should spend your money and invest in quality. However, if your budget allows it, it is great if you can also have a small, inexpensive autopilot on board. You are only going to ask this pilot to steer in calm and very light airs, so you will not be overworking it, which is why a small inexpensive cockpit mounted unit is all right. Steering quickly gets boring, but steering when powering for long periods is worse than any other kind.
Although we base these opinions on our own experience of cruising and dealing commercially with self-steering, these conclusions are borne out again and again when talking to returning cruising people. SAIL Magazine ran an article based on interview with twenty long distance cruising sailboats in Tahiti. These boats were from all over the world and had sailed thousands of miles to reach French Polynesia. All the boats except two had a vane gear. Of the two that did not both wished they had one. Electricity and keeping it flowing was a major concern on all twenty boats. Autopilots were found to be on one of two lists: the wish list or the broken equipment list.
These notes have been written with the average cruising sailboat in mind (45 feet +/- 10 feet). Good vane gear installations have been made on boats 20 feet long and even smaller. The upward limits for commonly available vane gear lie around 50 feet to 65 feet LOA. When a yacht gets larger than that a custom vane gear will have to be built as standard vanes do not have the strength of construction or the power to deal with the forces involved. On such large yachts, however, space and charging limitations do not exist as they do on a smaller boat. A large commercial type autopilot can be used and fed by a separate generator and a large battery bank. This solution is the more convenient for a very large sailboat.