What size Raymarine autopilot do I need for my boat?

Choose a Raymarine autopilot by your boat's fully loaded displacement and steering arrangement, then match the drive to a compatible actuator control unit. For hydraulic steering, size the pump from the steering cylinder's capacity; boat length alone is not a reliable guide.

Steering type and loaded weight

Identify what moves the rudder or outboard: a tiller, mechanical wheel steering, hydraulic cylinder or electronic steering system. This determines which drive you can fit.

Find the boat's displacement with fuel, water, crew, cruising stores, tender and additional equipment aboard. The brochure's empty displacement can substantially understate an older cruising yacht's working weight.

• Mechanical steering: check displacement, available mounting space and access to the rudder stock or quadrant.
• Hydraulic steering: record the cylinder manufacturer, model and capacity in cubic centimetres, plus whether there are multiple cylinders.
• Electronic steering: identify the engine and steering-system models and years. Compatibility requires a specific interface or approved installation.

Check that the steering moves freely before buying anything. Stiff cables, worn bearings and a badly balanced sail plan increase the load on every autopilot.

Tiller and wheel pilot limits

Raymarine's cockpit-mounted options have these published maximum displacement ratings:

• ST1000+ tiller pilot: 3,000 kg.
• ST2000+ tiller pilot: 4,500 kg.
• Evolution EV-100 Tiller: 6,000 kg.
• Evolution EV-100 Wheel: 7,500 kg.

These are displacement limits, not recommended targets for every passage. A heavily laden yacht near the limit benefits from a more substantial drive, particularly offshore. A larger display or different response settings will not increase the drive's mechanical capacity.

A yacht weighing 6,800 kg ready to sail falls within the EV-100 Wheel rating. If it carries substantial weather helm or regularly sails long passages in following seas, assess a below-deck drive before choosing the wheel pilot.

Tiller-pilot mounting geometry matters too. Follow the installation manual's specified distance from the rudder pivot, mounting height and bracket requirements. An improvised attachment changes mechanical advantage and available rudder travel.

Below-deck drives for heavier yachts

For yachts with suitable mechanical steering, Raymarine's electric linear drives have these displacement ratings:

• Type 1: up to 11,000 kg displacement.
• Type 2 short: up to 20,000 kg.
• Type 2 long: up to 22,000 kg.
• Type 3: up to 35,000 kg.