Sailboat autopilots

A sailboat autopilot is an electric or hydraulic device which holds the vessel on course in place of a person at the helm.

These devices are particularly useful when single-handing or sailing with a small crew, especially on long voyages. They also reduce strain on the crew while motoring in the absence of wind, when steering is more a chore than a pleasure.

When used with quadrant gear, the autopilot usually consists of a calculator, a helm angle sensor, a gyrocompass, an electro-hydraulic pump and piston and a control panel. Some also have a remote control.

For tiller steering, a simple motorized piston incorporates almost all these elements. Only a control screen and a gyrocompass sensor need be added. Some models for sailboats with medium-sized wheels use a belt attached directly to the wheel hub.

Linked to a dedicated wind vane, an autopilot can adjust point of sailing, steering as a function of the boat/wind angle. When connected to an on-board computer or the NMEA control panel, it can communicate with the rest of the vessel's instruments. Since these devices consume at least 10 amperes, there must be a reliable method of recharging the boat's batteries.

Choice will depend on vessel size, displacement and maximum speed, which help determine the autopilot's required power. Steering type and mechanism (tiller, wheel, hydraulic, cable, etc.) will also influence selection.