Autopilot Turn Patterns: U-Turn, Zigzag, and More

What are autopilot turn patterns?

Turn patterns are preset maneuvers that an autopilot can execute automatically. Instead of you turning the wheel or tiller, you select a pattern, and the autopilot steers the boat through that shape. These patterns are useful for searching a wide area, circling a fishing spot, or reversing course without constant manual input. When comparing marine autopilots, check which patterns each model offers.

The exact patterns available depend on the autopilot model and its control head. For example, Furuno's NavPilot 300 offers Zig-Zag, Orbit, Figure 8, and Spiral maneuvers as part of its Fish Hunter mode. Raymarine's Evolution autopilots, on the other hand, focus on standard course keeping and route following, with turn patterns being less prominent. Always check the maker's page for the specific modes your autopilot supports.

Common turn patterns explained

Here are the most common turn patterns you might see on a marine autopilot:

U-turn: This pattern reverses the boat's heading by 180 degrees. It is useful for returning to a spot you just passed or for turning around in a narrow channel. The autopilot calculates the turn based on the current heading and executes it smoothly.

Zigzag: This pattern steers the boat in a series of alternating turns, creating a zigzag path. It is often used for searching an area, such as when looking for a lost object or scanning for fish. The autopilot alternates between two headings, covering a wider swath of water.

Orbit: This pattern circles around a fixed point, keeping the boat at a constant distance. It is useful for circling a fishing spot or a man overboard location. The autopilot maintains a steady turn rate to keep the orbit tight.

Figure 8: This pattern traces a figure-eight shape, crossing over the starting point. It is useful for covering an area in a systematic way, often used in search patterns. The autopilot alternates between two orbits, one in each direction.

Spiral: This pattern starts with a wide circle and gradually tightens, or vice versa. It is useful for homing in on a target or for a systematic search. The autopilot adjusts the turn rate to create the spiral shape.

When to use each pattern

Choosing the right pattern depends on your goal. For reversing course, a U-turn is the most direct. For searching a large area, a zigzag or spiral covers more ground. For staying near a specific spot, an orbit or figure eight keeps you in the vicinity.

Fishing is a common reason to use turn patterns. Furuno's NavPilot 300 includes a Fish Hunter mode that can perform square, zigzag, circle, orbit, spiral, or figure-eight maneuvers around a target. This is useful for trolling around a fish finder target or for keeping the boat in a productive area. If you fish often, look at Furuno autopilots for these advanced patterns.

Man overboard situations also benefit from turn patterns. The same Fish Hunter mode can be used for MOB, helping the boat circle back to the person in the water. However, always prioritize safety and follow proper MOB procedures; an autopilot is a tool, not a replacement for a lookout.

How to select a turn pattern

Selecting a turn pattern is typically done through the autopilot's control head. The process varies by brand and model. On Furuno's NavPilot 300, you use the gesture controller or the display to choose a pattern. On other autopilots, you might navigate a menu on the control head or a connected chartplotter. For guidance on control heads, see autopilot control head options.

Before using a turn pattern, make sure the autopilot is engaged and the boat is at a safe speed. The autopilot will handle the steering, but you should monitor the boat's surroundings. The U.S. Coast Guard's Boating Safety page emphasizes the importance of keeping watch and being aware of your environment at all times.

Some patterns, like those in Fish Hunter mode, require additional sensors. For example, Furuno notes that a Rudder Reference Unit (RRU) is required to enable Fish Hunter mode on some models. Check the maker's page for the specific requirements of your autopilot.

Turn patterns and your boat's steering

The type of steering on your boat affects how turn patterns work. Hydraulic steering systems, common on powerboats, respond differently than mechanical systems on sailboats. The autopilot's drive unit must be matched to your steering type for the patterns to execute properly. Learn more about drive types and hydraulic steering.

Raymarine's drive unit selection guide explains that the drive unit interfaces with your vessel's steering system. They offer hydraulic pumps, rotary drives, and linear drives for different setups. If you are unsure about your steering type, consult an authorized dealer.

For boats with steer-by-wire systems, such as those with digital drive-by-wire, the autopilot may integrate directly with the engine controls. This allows for smoother and more precise turns. Check the maker's page for compatibility with your specific helm system. See steer-by-wire autopilots for more.

Safety considerations with turn patterns

Turn patterns are automated, but they are not a substitute for attentive boating. Always keep a lookout for other vessels, obstacles, and swimmers. The U.S. Coast Guard's Boating Safety page provides resources on safe boating practices, including navigation rules and float plans.

Before engaging a turn pattern, ensure the area is clear and you have enough room to maneuver. Some patterns, like a U-turn, require more space than others. Be especially cautious in narrow channels or crowded anchorages.

If something goes wrong, you should be able to disengage the autopilot quickly. Most control heads have a standby or manual override button. Familiarize yourself with your autopilot's controls before relying on turn patterns.

What to look for when buying

When comparing autopilots, check the list of turn patterns each model supports. Some brands, like Furuno, advertise specific patterns such as zigzag and orbit. Others may not offer these at all, focusing instead on basic course keeping.

Consider how you plan to use the boat. If you fish often, a model with Fish Hunter mode or similar features might be worth it. If you mostly cruise, you may not need advanced turn patterns. For a balanced choice, browse complete autopilot packs.

Also, consider the control head. A model with a clear display and intuitive controls makes selecting patterns easier. Some control heads, like those from Raymarine, offer a rotary knob for quick adjustments. Others use touchscreens or gesture controllers. See autopilots with control head for options.

Finally, think about integration with your existing electronics. Turn patterns often work best when the autopilot is connected to a chartplotter or fish finder, as this allows the autopilot to respond to targets. NMEA 2000 connectivity is a common way to achieve this, as described by the National Marine Electronics Association. Learn about NMEA 2000 connectivity.

What to pick for your situation

Questions

What is a U-turn pattern on an autopilot?

A U-turn pattern automatically reverses the boat's heading by 180 degrees. It is useful for returning to a spot you just passed or for turning around in a confined area. The autopilot calculates the turn based on the current heading and executes it smoothly.

Can I use turn patterns for man overboard situations?

Some autopilots, like the Furuno NavPilot 300, have a Fish Hunter mode that can be used for MOB. This mode can perform maneuvers like orbit or figure eight to circle back to the person. However, always follow proper MOB procedures and keep a lookout; an autopilot is a tool, not a replacement for safety practices.

Do all autopilots have turn patterns?

No, turn patterns are not universal. Some autopilots focus on basic course keeping and route following, while others, like Furuno's NavPilot series, offer specific patterns such as zigzag, orbit, and figure eight. Check the maker's page for the features of a particular model.

What sensors do I need for turn patterns?

Some turn patterns require additional sensors. For example, Furuno notes that a Rudder Reference Unit (RRU) is required to enable Fish Hunter mode on some models. Also, a heading sensor is essential for any autopilot to know the boat's direction. Check the maker's specifications for your autopilot.

Can I use turn patterns with any steering system?

Turn patterns work with any steering system that the autopilot is designed to control, whether hydraulic, mechanical, or steer-by-wire. The drive unit must be matched to your steering type. Consult the maker's page or a dealer to ensure compatibility.

Are turn patterns safe to use in crowded waters?

Turn patterns should be used with caution in crowded waters. Always keep a lookout and ensure you have enough room to maneuver. The U.S. Coast Guard's Boating Safety page emphasizes the importance of maintaining a proper watch and following navigation rules. Disengage the autopilot if you need to take manual control.