Installing and using wind vane steering
Simple in theory, this classic steering system makes a perfect companion to an autopilot
Few things are more enjoyable than steering a boat on a beautiful day. Until you've been doing it for hours upon hours and you've got many miles left to go. That's when a self-steering system makes that passage even better. And whether you want to admit it or not, a self-steering system will likely steer straighter than a human for long periods, shaving miles and time off your passages.
The modern answer to self-steering is the autopilot. Autopilots are great but they are not without their weaknesses. Autopilots, along with refrigeration, are the largest consumer of electricity aboard, and traditionally autopilots have not been 100% reliable. Self-reliant practices state that a cruiser should carry a second autopilot in case of a problem, and some people even go to the work of installing a second redundant system so they can hot-swap to a working system should one fail.
A traditional self-steering method is the transom-mounted wind vane. These systems consist of a wind sensitive vane and a steering device. As the vane senses changes in the wind it activates the steering system to return the boat to the selected point of sail. The steering system is very typically the rudder of the boat itself. If you have seen wind vanes in boat shows or in your marina, you have probably seen what looks like a little rudder. This rudder is not used to steer the boat but to generate power via water resistance to turn the wheel of the boat.
The wind vane senses the wind and the movement of the vane turns the little rudder in the water, little rudder wants to straighten back out due to the water pressure on it and this straightening force, via some rope and pulleys, is transmitted to the wheel or rudder on the boat, and the boat is steered back on course. The system works well if properly engineered and installed, all without power, electronics or noise.
Unlike autopilots, which do best in light-to-moderate conditions, wind vanes steer very well in heavy conditions and do not work well at all in very light winds, making the systems great complements of each other.
Autopilots and wind vanes steer differently. A wind vane will steer to a constant point of sail, a relative angle to the wind. The autopilot, by default, steers to a compass course or to a GPS waypoint. In a passagemaking situation steering to a course or waypoint is important, but in heavy conditions steering to the wind has its benefits.
A a hybrid solution of a quality autopilot and wind vane system may be the best option for serious passagemaking. The autopilot will work great when motoring or for short passages and the wind vane will be the workhorse on longer passages.
Installing a wind vane does take a bit of planning. They work best when centered on the transom and set at the manufacturer's recommended height.
The second consideration is running the steering lines to the wheel. There are two roughly quarter-inch lines that need to run cleanly from the vane to the steering wheel of the boat. You want these runs to be as short and smooth as possible. You can add blocks to deflect and turn the lines, but every turn adds friction. Remember that these lines are only deployed when the vane is in use.
The actual installation should be fairly straightforward as most vanes on the market are adaptable to a variety of hull configurations, and some will even come customized to bolt right on. Standard mounting protocols apply. Through-bolt everything with proper bedding, and use backing plates or at least large fender washers on the inside.
Using a wind vane is a little more complicated than just pushing "Auto" on your autopilot, but not much more. The first step is to deploy the gear. The wind paddle is typically removed for storage and the rudder folded up, but both can be deployed in just a few minutes. Next, the control lines are connected to the wheel; this is typically done with knots or a bit of hardware. With the vane deployed, set the boat on course and balance it for the desired point of sail, then adjust the vane to match and engage the wheel. At this point you'll need to evaluate how the vane is sailing, making further adjustments by sail trim.
Course adjustments are made by turning the wind paddle to match the new course, and trimming to it. If you need to disengage the system to hand steer for short periods of time, simply disengage the steering wheel attachment, but leave all the other gear in place.
The key to success in using any self-steering system is to balance the boat. A boat that is poorly trimmed will not sail well with a human, mechanical or electronic helmsman. Wind vanes steer better on some points of sail, a steady beat offers the best performance, the wind provides lots of steering input signal to the vane.
With a self-steering system you'll sail faster, straighter, and can spend more time concentrating on the more enjoyable aspects of sailing. A hybrid system of a wind vane backed up by an autopilot will provide a robust self-steering system for most all conditions.