Raymarine E90W User Reference Handbook page 95

Menu item
System Datum
Selecting the cartography setup menu
In the chart application:
1. Press the MENU button.
2. Select the Cartography Setup menu item.
Using the chart
Description
In order for your GPS and chart to correlate accurately with your paper
charts, they must be using the same datum. The default datum for your
display is WGS1984. If this is not suitable, you can change the setting.
When you change the datum setting, the chart grid will subsequently
move according to the new datum, and the latitude/longitude of the
cartographic features will also change accordingly. The system
attempts to set up any GPS to the new mode, and indicates whether
this was successful or not.
Note: Raymarine recommends that you check the displayed
vessel position in the chart application against your actual proximity
to a known charted object. A typical GPS has an accuracy of
between 5 and 15 m.
Options
• 1.0 nm / sm / km
• WGS1984 (default)
• List of available datum
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