Furuno FR1500 Mk3 Operator's Manual page 27

If relative motion is selected, it is also possible to read CPA (Closest Point of Approach) by
using a VRM as shown below (Figure (a)). If the EBL passes through the sweep origin (own
ship) as illustrated (Figure (b)), the target ship is on a collision course.
5. To return the EBL origin to the own ship position, press the [EBL OFFSET] key again.
CURSOR
340
330
320
310
A
300
290
A'
280
270
260
250
240
230
EBL 1 220
210
200
EBL
150.3°R
(a) Evaluating the target ship course in RM
000 010 VRM 1
350
020
030
040
050
060
070
080
090
100
110
120
130
140
150
160
VRM
190 170
180
3.85 NM
CURSOR
320
310
300
290
280
270
260
250
240
230
EBL 1 220
EBL
100.3°R
(b) Target ship on collision course
-1.15-
000 010 VRM 1
350
020
340
330 030
040
050
A
A'
130
140
210
150
200
160
190 170
180
3.85 NM
060
070
080
090
100
110
120
VRM