Furuno FAR-2107 - Manual (Page 151)

3. ARP OPERATION
3-19
3.10 Past Position Display
The ARP displays equally time-spaced dots marking the past positions of any
targets being tracked.
A new dot is added every minute (or at other preset time intervals) until the
preset number is reached. If a target changes its speed, the spacing will be
uneven. If it changes the course, its plotted course will not be a straight line.
(a) Ship turning (b) Ship running
straight (c) Ship reduced
speed (d) Ship increased
speed
Past position display
3.10.1 Displaying and erasing past position points, choosing past
position plot interval
1. Roll the trackball to choose the PAST POSN box at the right side of the
screen.
PAST POSN REL 2MIN
PAST POSN box
2. Push the left button to choose plot interval desired: OFF, 30 seconds, 1, 2, 3
or 6 minutes. Choose OFF to erase all past position points and deactivate
the past position display.