Autopilot Wind Mode: How It Works

What is wind mode on an autopilot?

Wind mode is a steering mode on some sailboat autopilots. Instead of holding a compass heading, the autopilot steers to maintain a set angle between the boat and the apparent wind. The wind angle is measured by a wind sensor, often part of the boat's instrument system, and the autopilot adjusts the rudder to keep that angle constant.

This is useful when you want to hold a consistent point of sail, such as close-hauled or a reach, without constantly adjusting the helm as the wind shifts. The autopilot does the work of responding to changes in wind direction, so you can focus on sail trim or other tasks.

Wind mode is not a standard feature on all autopilots. It is more common on models designed for sailboats, like the Raymarine EV-200 Sail Pilot or the Furuno NavPilot 300. Powerboat autopilots typically do not have wind mode because they do not rely on wind for propulsion.

• Wind mode steers to a wind angle, not a compass heading.
• It uses apparent wind data from a wind sensor.
• It is found on sailboat-specific autopilots.
• It helps maintain a consistent point of sail.

Apparent wind vs true wind

Apparent wind is the wind you feel on the boat as it moves. It is a combination of the true wind (the wind over the water) and the wind created by the boat's own motion. The apparent wind angle is what the sails see, and it is what a wind sensor measures. Understanding the difference is part of choosing an autopilot for a sailboat, as explained in sailboat vs powerboat autopilots.

Wind mode on an autopilot typically uses apparent wind angle, not true wind. This is because the sails are trimmed to the apparent wind, and maintaining a constant apparent wind angle keeps the sails working consistently. True wind angle would require the autopilot to account for boat speed and heading, which is more complex and less common in consumer autopilots.

When you set wind mode, you choose a target apparent wind angle, for example 30 degrees. The autopilot then steers to keep the boat at that angle to the apparent wind. If the wind shifts, the autopilot adjusts the course to maintain the set angle.

• Apparent wind is the wind felt on the moving boat.
• True wind is the wind over the water, independent of boat motion.
• Wind mode uses apparent wind angle.
• The autopilot adjusts course to keep the set angle.

How wind mode works

In wind mode, the autopilot receives wind angle data from a wind sensor, which is often part of a networked instrument system like NMEA 2000. The autopilot compares the current apparent wind angle to the target angle you set. If the wind angle changes, the autopilot calculates a course correction and moves the rudder to bring the boat back to the target angle.

The autopilot's course computer processes the wind data and controls the drive unit, which physically turns the rudder or wheel. The drive unit can be a tiller pilot, a wheel drive, a linear drive, or a hydraulic pump, depending on the boat's steering system. The autopilot continuously adjusts the rudder to keep the boat on the desired wind angle.

Wind mode is different from heading mode, where the autopilot holds a compass course. In heading mode, the autopilot ignores wind shifts and maintains the same compass heading. In wind mode, the autopilot allows the heading to change as needed to keep the wind angle constant. For a broader look at how autopilots compare, see the main autopilot guide.

• Wind sensor provides apparent wind angle data.
• Autopilot compares current angle to target angle.
• Course computer controls the drive unit to adjust the rudder.
• Heading changes to maintain the wind angle.

What to expect from wind mode

Wind mode is a convenience feature, not a replacement for attentive sailing. The autopilot will maintain the set wind angle, but you still need to trim sails, watch for traffic, and keep a lookout. The U.S. Coast Guard Boating Safety page emphasizes the importance of boating safety and education, and an autopilot does not relieve you of the duty to keep watch.

Wind mode works best when the wind is relatively steady. In gusty or shifty conditions, the autopilot will make more frequent corrections, which can be tiring for the drive and may not hold the angle as smoothly. You may need to adjust the target angle as the wind strength changes.

Wind mode is often used in conjunction with other autopilot features, such as route following or tacking. Some autopilots allow you to tack from one wind angle to the other with a single command. Check the product details to see what features are included.

• Wind mode maintains a set wind angle, not a heading.
• You still need to trim sails and keep watch.
• Frequent wind shifts may require more corrections.
• Some autopilots offer tacking from wind mode.

How to check if an autopilot has wind mode

When comparing autopilots, look for wind mode in the product specifications or feature list. Sailboat-specific models are more likely to have it. For example, the Raymarine EV-200 Sail Pilot is designed for mid-sized sailboats with mechanical steering, and the Furuno NavPilot 300 is an adaptive autopilot that can be used on sailboats. You can also explore complete autopilot packs to see which ones list wind mode.

Wind mode requires a wind sensor. If the autopilot does not include a wind sensor, you may need to purchase one separately or connect to an existing wind instrument on your boat. The wind sensor must be compatible with the autopilot's network, such as NMEA 2000. For more on sensor requirements, see the article on autopilot sensor requirements.

If you are unsure whether a specific autopilot has wind mode, check the maker's product page or contact a dealer. The product listing on this site shows the stated details, but wind mode may not be listed. The maker's page is the best source for feature information.

• Check the product specifications for wind mode.
• Sailboat-specific models are more likely to have it.
• A wind sensor is required, which may be sold separately.
• The maker's page is the best source for features.

What to pick for your situation

Questions

What is the difference between wind mode and heading mode?

Heading mode holds a compass course, ignoring wind shifts. Wind mode steers to a set apparent wind angle, allowing the heading to change as the wind shifts. Learn more in the main autopilot guide.

Do all sailboat autopilots have wind mode?

No, not all. Wind mode is a feature that may be included on sailboat-specific models, but it is not universal. Check the product details or the maker's page. See the sailboat autopilot guide for models that may include it.

Do I need a wind sensor for wind mode?

Yes, wind mode requires a wind sensor to measure apparent wind angle. The sensor may be included with the autopilot or sold separately, and it must be compatible with the autopilot's network. Review sensor requirements for more.

Can I use wind mode on a powerboat?

Wind mode is typically not available on powerboat autopilots because powerboats do not rely on wind for propulsion. It is a sailboat-specific feature. See powerboat autopilots for alternatives.

Will wind mode keep me on a safe course?

Wind mode maintains a wind angle, but it does not replace a lookout. You are still responsible for keeping watch and avoiding hazards, as emphasized by the U.S. Coast Guard Boating Safety page.