Garmin GPSMAP 2006C User Manual
Page 82
 
73
Reference
headings based upon a true north reference. ‘Grid’ provides headings based on a grid north refer-
ence (and is used in conjunction with the grid position formats listed on page 72). ‘User Mag Var’
allows you to specify the magnetic variation at your current position and provides magnetic north
heading references based upon the variation you enter.
To enter a user defined magnetic variation:
1. With the ‘Heading’ field set to ‘User Mag Var’, highlight the heading reference field (immediately to the
right) and press ENTER/MARK.
2. Use the DATA ENTRY keys to enter the magnetic variation at your current position and press ENTER/
MARK.
WARNING: If ‘User Mag Var’ is selected, you must periodically update the magnetic varia-
tion as your position changes. Using this setting, the unit will not automatically calculate 
and update the magnetic variation at your present position. Failure to update this setting 
may result in substantial differences between the information displayed on your unit and 
external references, such as a magnetic compass. 
• Distance, Speed and Altitude— lets you select the desired units of measure for distance, speed and
altitude readouts in ‘Nautical’ (nm, kt, ft), ‘Statute’ (mi, mh, ft), or ‘Metric’ (km, kh, m) terms.
• Depth— lets you select the desired units of measure for depth in Feet (ft), Fathoms (fa), or Meters
(m).
• Temperature— lets you select the desired units of measure for temperature in Fahrenheit (°F) or
Celsius (°C).
The Units tab settings will affect how navigation information 
is displayed on the GPSMAP 2006/2010. The ‘User’ datum is 
based on a WGS-84-Local datum and is an advanced feature 
for unlisted or custom datums. Setup is available for each by 
pressing the appropriate SOFT KEY option. To learn more, 
check your local library or the world wide web for educational 
materials on datums and coordinate systems. When in doubt, 
seek assistance.
If you are using a map or chart in conjunction with your GPS, 
make sure the settings under the ‘Units’ tab of the GPSMAP 
2006/2010 match that of the map or chart. This information 
should be displayed somewhere on the map or chart. If the 
information is not present, contact the map or chart maker to 
determine what position format, datum, heading and units of 
measure are being used for the map or chart.
You may manually enter a magnetic variation.
Main Menu: Units Tab