Compass Deviation; Check The Compass Heading Data - Raymarine LIGHTHOUSE 3 Advanced Operation Instructions

The linearization process will start automatically after your vessel has turned approximately 100° at a
speed of between 3 –15 knots. Linearization requires no user input, however at least a 270° turn
is required before linearization can complete. The progress bar will fill to indicate progress, the
progress bar will turn Red if the process is paused or otherwise interrupted. Time it takes to complete
the linearization will vary according to the characteristics of the vessel, the installation environment of
the EV unit, and the levels of magnetic interference at the time of conducting the process. Sources
of significant magnetic interference may increase the time required to complete the linearization
process. Examples of such sources include:
• Marine pontoons
• Metal-hulled vessels
• Underwater cables
You can speed-up the linearization process by completing a full 360° turn (at a speed of 3 – 15 knots).
You can also restart the linearization process at any time by selecting the Restart Compass from the
Pilot set-up menu: Homescreen > Settings > Autopilot > Pilot set-up.
Once the initial linearization is completed the Maximum compass deviation value is displayed under
the Pilot set-up button on the Autopilot settings page.

Compass deviation

If the reported deviation is 45° or higher, it is highly recommended that the EV sensor is moved and
re-installed in a location which is subject to less magnetic interference.
Note:
If "- -" is displayed as the Deviation value, it means that linearization has not been successfully
completed yet.

Check the compass heading data

As part of the autopilot system commissioning process, it is recommended that you check the
compass heading value displayed, against a good known heading source on various headings.
Note:
Once the linearization process has completed, it is possible that the heading value may have a
slight offset of 2 to 3 degrees. This is common where installation space is limited, and the EV
sensor cannot be properly aligned to the vessel's longitudinal axis. In this case, it is possible
to manually adjust the Compass offset value.
Autopilot control
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