What are Laylines and how do they work

What are laylines?

In simple terms, >Laylines represent the most efficient Way of reaching your destination, given the presentwind conditions – by sailing along your target >Laylines you can maximize your >Velocity Made Good (VMG).
• “Mark Laylines” display the target Course to sail to reach the destination
• “Boat Laylines” display the target Course of the yacht
The point where the two sets of >Laylines intersect can be thought of as the Tack (or gybe) point.
Zeus also offers the ability to correct >Laylines for the effects of the Current Tide measurement.

 

How do they work?

Laylines are based on the True Wind Direction (TWD) from your instrument system along with either (1) your target upwind and downwind sailing angles or (2) your actual sailing angles.


Target angles provide you with the most efficient sailing angle, while actual angles use real data from the live measurements.
• Targets are set by either entering your upwind and downwind sailing angles into Zeus
• Actual data uses your Current True Wind Angle

 

What can I See?

laylines

Video example

ACTUAL >Laylines v MANUAL LAYLINES

ACTUAL LAYLINES
Are incredibly useful for cruising yachts, where the focus is more on tacking in the right place to Stay safe rather than sailing at optimum performance all the time. In this mode the >Laylines are calculated from the Current True Wind Angle, either directly from the instrument system (if available) or calculated from Boat Speed and Apparent Wind Angle. This setting gives you a realistic tacking angle based on your Current performance.

 

MANUAL LAYLINES
Should be selected if you do not have an instrument system that can send Polar target information to the Zeus system but you want to sail to a target wind angle.
Manual >Laylines allow the user to preset the upwind and downwind sailing angles for the Boat. Target angles vary by Boat and conditions, but angles of 45º upwind and 165º downwind are a good starting point.

 

TIDAL CORRECTION
Zeus offers the user the ability to correct the >Laylines for tidal effects. Unlike PC-based chartplotters, which often use tidal models to predict tidal effects along your entire route, the B&G Zeus uses the live instrument data to calculate the tidal effect on the Boat, and applies this information to the laylines. This means the user does not have to worry about updating the tidal model.
 
laylines2

 

Laylines feature in many of the new B&G chartplotters, such as: Zeus 7 TouchZeus 8 Touch and Zeus 12 Touch; and Vulcan 5 FS and Vulcan 7 FS.