Let the wind do the steering

Andrew Simpson looks at pendulum servo self-steering gears, and describes how to get the best out of them

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Wind vanes, to some, are an ugly protuberances, burdening the stern of otherwise handsome yachts. But to many an offshore sailor they are a godsend, an inexhaustible crew member who will toil night and day without complaint or sustenance.

And without wind vane self-steering gears-often simply called vane gears - this particular sailor would be reluctant even to put to sea.

Yet, if you ask around, experiences seem mixed. Some skippers find them obliging and obedient; others have had less consistent results.

Many say they rely on their electronic autopilots for shorter passages, preferring push-button simplicity to the relative complexities of setting up their vane gears, though I find this surprising, since it takes no more than a few seconds to rig and engage a modern, well-engineered gear.

But there's no doubt that vane gears can seem temperamental, and perhaps with good reason. Uncomplaining and tireless though they might be, they won't be treated disrespectfully.

To get the best out of them they must be appreciated, understood, even cosseted. The more you use them and become familiar with their ways, the better they will serve you.

Vane gears work by sensing the wind direction and converting that information into an action that will steer the boat on a course relative to it.

This can either be via a direct linkage to their own auxiliary rudder, such as on the well-regarded Hydrovane, or by harnessing the waterflow past the hull to create a powerful servo effect which, in turn, either works directly on the boat's primary steering or, again, on a smaller auxiliary rudder.

The first type is known as 'direct drive', and the second as servo-pendulum. There's also another servo type which uses trim tabs on the main rudder, but these are only rarely seen nowadays.