46 GPSMAP 4000 Series Owner’s Manual
Using Radar
USinG
radar
To enable the guard zone:
From the Home screen, select Radar > Sentry > Menu > Sentry Setup > Enable Guard Zone.
To adjust the guard zone boundaries:
1. While the guard zone is on, from the Radar screen, select Menu > Sentry Setup > Adjust
Guard Zone > Move Guard Zone.
2. Select an option:
Corner 1 (and Corner 2): Denes a guard zone that does not completely encompass the
boat. Use the Rocker as indicated by the arrows ( and ) to dene the size of the guard
zone. Use Corner 1 or Corner 2 to change the reference point.
Circular: Joins the guard zone to completely encompass the boat. Use Corner 1 or Corner 2
to adjust the size.
CircularCorner 1 Corner 2
Radar Targeting
NOTE: MARPA requires the use of a heading sensor. The heading sensor must output the NMEA 0183
sentence HDM or HDG.
1. From the Radar screen, use the Rocker to begin targeting. As you move the target over objects
on the radar, target options appear along the right side of the screen.
Cruising Screen - Targeting
Heading line
Target options
Target
2. Select an option:
Select Create Waypoint to mark a waypoint at the targeted object or location.
Select Acquire Target to assign a Mini Automatic Radar Plotting Aid (MARPA) tag to the
targeted object.
Select Drop VRM/EBL to set the Variable Range Marker (VRM) and Electronic Bearing Line
(EBL) to measure range and bearing to a target.
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