Furuno FCR-21x9-BB Operator's Manual page 61

If the position of the CCRP results in a part of the bearing scale not being distinguish-
able, that part of the bearing scale is indicated with appropriate reduced detail.
A failure of the heading sensor input will cause the heading readout to disappear, and
the Alert 450 "Heading Sensor Not Available" or "Gyro COM1 Error" (a number be-
tween 250-259 according to gyro no.) appears in the [Alert] box.
When own ship reaches a point corresponding to 50% of the radius of the display, own
ship position is automatically reset to a point of 75% radius opposite to the extension
of the heading line passing through the display center. You can also reset the own ship
symbol manually by pushing the CU/TM RESET key, or click the [CU/TM reset] button
on the InstantAccess bar.
North marker
Heading
line
(a) True motion
is selected
(b) Own ship has reached a
point 50% of display radius
2. RADAR, CHART RADAR OPERATION
(c) Own ship is automatically
reset to 75% of display radius
2-5