Raymarine LIGHTHOUSE 3, Advanced Operation Instructions

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[If you would prefer not to define the search rectangle dimensions using the major and minor axis,
the rectangle can be defined by setting the coordinates of each corner point instead]:
i. Enter the coordinates of each corner point 1–4.
Note:
• The corner coordinates need to form a rectangle. If the coordinates are not suitable then you
will not be able to create the search route.
• The CSP must be on one of the sides of the search pattern.
• For a Creeping Line search pattern the CSP must be located along one of the longer sides.
• For a Parallel Line search pattern the CSP must be located along one of the shorter sides.
• The CSP must be on a bearing of between 85° to 95° (i.e. right angle ± 5°) from the previous side.
• The CSP should be half a track width from the corner point.
8.13 Laylines
Laylines are used in sailing to show how far the vessel must sail on the current tack in order to make
a target waypoint after tacking, given present wind conditions.
When a layline is used to calculate the route to a waypoint, it will take into account a number of factors
to provide a better alternative course, compared to simply navigating in a straight line to a waypoint.
The reason why laylines are a more efficient way to sail to a specific point is because they’re
based on True Wind Direction (TWD) and either: a) fixed upwind / downwind sailing angles, or b)
the use of polars to reflect the performance of your particular vessel. In this respect, sailing along
laylines maximizes your Velocity Made Good (VMG) to windward. Another reason why laylines
are more accurate is because they can also be configured to account for tidal current, as well as
the leeway of your vessel.
To ensure the layline calculations are as accurate as possible, it’s important to ensure that the
following settings are correctly configured:
• Boat details (specifically those relating to sailing) : Homescreen > Settings > Boat details
• Laylines settings : Chart app > Menu > Settings > Laylines
For more information on these settings, refer to: p.85 — Boat details
and p.186 — Laylines settings
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