34 GPSMAP 640 Owner’s Manual
Marine Mode: Advanced Conguration
Factory Settings—erase all user settings and return the device
to factory default settings.
Event Log
—view a list of system events. Select an event to
view additional information.
Save to Card—save system information to an SD card. It is
advised to use this function only if instructed to do so by a
Garmin Product Support Specialist.
Speed Sources—specify the sensor used for Wind numbers. Touch
Wind to toggle between Water (from a water speed sensor) and
GPS (from the calculated GPS speed).
Usage Mode
—change to automotive mode.
Changing Units of Measure
From the Home screen, touch Congure > Units.
System Units
—specify system-wide units of measure: Statute
(mh, ft, ºF), Metric (kh, m, ºC), Nautical (kt, ft, ºF), or Custom.
Touch Custom to individually dene units of measure for:
Depth—set the units of measure for depth to Feet, Fathoms, or
Meters.
Temperature
—set units of measure for temperature to
Fahrenheit (ºF) or Celsius (ºC).
•
•
•
•
•
NOTE: You must be receiving NMEA sonar depth data and
temperature data to view depth and temperature information.
Distance—set the units of measure for distance readings (Miles,
Kilometers, or Nautical Miles).
Speed—set the units of measure for Vessel Speed and for Wind
Speed readings (Miles Per Hour, Kilometers Per Hour, or
Knots).
Elevation
—set the units of measure for elevation readings
(Feet or Meters).
Atmospheric Pressure
—set the units of measure for
atmospheric (Millibars or Inches of Mercury) pressure
readings.
Heading—set the reference used in calculating heading
information.
Auto Mag Var (
Automatic Magnetic Variation)—automatically
set the magnetic declination for your location.
True
—set true north as the heading reference.
Grid—set grid north as the heading reference (000º).
User Mag Var
—set a custom magnetic variation value.
•
•
•
•
•
•
•
•
