Furuno NAVNET GD-1920C - Manual (Page 44)

2. RADAR OPERATION
2-15
2.17 Using the Offset EBL
The offset EBL can be used to predict a potential collision course. It can also be used to
measure the range and bearing between two targets.
2.17.1 Predicting collision course
The procedure below may be used to check if a radar target is on a potential collision
course with your vessel.
1. Press the
EBL/VRM key to show the EBL/VRM soft keys.
2. Press the EBL1 ON soft key to turn on the EBL1.
3. Press the OFFSET soft key. The origin of EBL1 moves to the cursor position, which is
marked with an “X.”
4. Use the Trackball to place the cursor on the radar target which looks like it might be on
a collision course with own ship.
5. Push the ENTER knob to fix the origin position.
6. After waiting for a few minutes (at least three minutes), rotate the ENTER knob so the
EBL bisects the target at the new position. If the target tracks along the EBL towards the
center of the display (your ship’s position), the target may be on a collision course with
your vessel.
To cancel the offset EBL, press the OFFSET soft key.
EBL
VRM
VRM1
ON
VRM2
ON
359.9 ˚R
11.70
nm
+
Initial target
position
Target tracked
here
OFFSET
EBL2
ON
EBL1
45.0˚R
VRM1
-.---nm
EBL1
ON
12/
H-UP
3nm
LP
319. 9
°
M
Predicting collision course with the offset EBL