You'll have to get a tiller pilot, duh!!!
Raymarine makes a heavy duty one that might
work. IIRC someone used one of these for a
cruise through the
Caribbean and halfway to
Tahiti before it finally gave out.
Raymarine was horrified that they even tried using it. The Westsail has a pretty heavy
helm under sail that tiller pilots just aren't built to handle.
The Raymarine pilot used to be called an X5 but think it's now called an EV-1. It's only rated to 13,500 pounds
displacement, though.
Simrad makes a self contained unit with about the same rating. Don't know of other sources of supposedly heavier duty tiller pilots. If you just want it for
steering under
power, the
Simrad would be cheapest way to go and would probably just fine.
If you have a vane, and you are a few sandwiches short of a picnic if you don't cause the
boat is steered so well by a Pendulum Servo Vane, you could
work out a way to attach a
cheap tiller pilot to that. Would work for sailing but might not under
power. The prop is close to the vane's
rudder and the prop wash probably wouldn't allow it to work very well. Never tried one on our
boat but the vane
rudder danced around an awful lot under power. Easy to test out, just try and have the vane steer while you input heading into the vane by hand while under power.