NorthStar EXPLORER 657 Installation And Operation Manual page 91

Navigation data
The boat is sailing from the start to the destination and has moved off the plotted course from the start
to the destination.
BRG Bearing to Destination: Bearing to the destination from the boat.
BRG Bearing to cursor: Bearing to cursor from boat (cursor mode, see section 3-2-1 [note the -1 added
there])
CDI Course Deviation Indicator: When the boat is navigating to a point, the chart and highway
windows show a parallel line on either side of the plotted course. These two lines are called the
Course Deviation Indicator (CDI) lines. The distance from the plotted course to a CDI line is the
CDI scale.
Set the CDI scale (see section 17-2) to the maximum distance that the boat should deviate from
the plotted course. The chart and highway windows show the CDI lines, which are like a highway
over the water where the boat will move. The windows show how far the boat has deviated from
the plotted course and if the boat is approaching a CDI line. If the XTE alarm is enabled (see
section 17-9) an alarm will sound if the boat reaches a CDI line.
COG Course Over Ground: Direction in which the boat is moving over the ground.
CTS Course To Steer: Optimum course to steer to return to the plotted course.
DTG Distance To Go: Distance from the boat to the destination.
ETA Expected Time of Arrival: At the destination, assuming that SOG and COG remain constant.
DST Distance from boat to cursor (cursor mode, see section 3-2)
SOG Speed Over Ground: Current boat speed over the ground. This is not necessarily the same as
the boat speed through the water nor the speed at which it is approaching the destination.
STR Steering: The diff erence between COG and CTS.
TTG Time To Go: The estimated time to reach the destination.
XTE Cross Track Error: The distance from the boat to the nearest point of the plotted course. XTE
may have a letter: R means steer to the right to return to the plotted course, L means steer to
the left.
VMG Velocity Made Good: The speed at which the boat is approaching the destination.
Destination
DTG (distance)
VMG (speed)
SOG (speed)
COG
STR
CTS
Plotted
course
Start
BRG
Boat position
Northstar Explorer 657 Installation and Operation Manual
Destination
Plotted
XTE
course
(distance)
Boat
position
CDI scale
CDI scale
(distance)
(distance)
Start
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