Si-tex Explorer Nav Pro User Manual page 74

● Tide Info
Calculates the tide heights for any past or future date and as a by-product of this calculation will
also display the Maximum and Minimum Tide height and time for the day selected plus the times
of Sunrise and Sunset. At some chart levels, the chart plotter will display a new Tide Diamond
Symbol for every Port or tide point in the database covered by that particular DATA MEDIA.
● Tracks & Routes
Recommended and established routes for ships at sea, including traffic separation schemes,
deep water routes.
● TTG = Time To Go
Estimated time needed to reach your destination, based on your current speed and the distance
to destination.
● TWA = True Wind Angle
Angle of the Wind relative to a fixed point on the earth.
● TWS = True Wind Speed
Velocity of the Wind relative to a fixed point on the earth.
● Underwater Objects
Objects like obstruction, wreck, cable...
● User Point
Object you place on the chart identified by its coordinates and displayed on the screen with a
reference symbol (see Mark, Waypoint).
● UTC = Universal Time Coordinated
Time scale based on the rotation of the earth that is used by most broadcast time services.
● UTM = Universal Transverse Mercator
Metric Grid system used on most large and intermediate scale land topographic charts and maps.
● Variation
Angle between the magnetic and geographic meridians at any place, expressed in degrees West
or East to indicate the direction of magnetic North from true North. It changes from point to point,
and (at the same point) with time.
● VMG= Velocity Made Good
Destination closing Velocity. The VMG is calculated using the current speed of the vessel (SOG)
and the difference between the current vessel course and the bearing to the destination.
● WAAS = Wide Area Augmentation System
The Federal Aviation Administration (FAA), in cooperation with other DOT organizations and DOD,
is augmenting the GPS/SPS with a satellite-based augmentation system, the WAAS. It will
provide a signal-in-space to WAAS users to support en route through precision approach
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Chart Plotter - User Manual