Furuno NAVNET 1823C - Manual (Page 47)

2. RADAR OPERATION
2-11
2.10 Measuring the Range
You can measure the range to a radar target three ways: by the range rings, by
the cursor, and by the VRM (Variable Range Marker).
2.10.1 Measuring range by range rings
Count the number of rings between the center of the display and the target.
Check the range ring interval and judge the distance of the echo from the inner
edge of the nearest ring.
To turn the range rings on, do the following:
1. If not displayed, press the [HIDE/SHOW] key to show the radar soft keys.
2. Press the RADAR DISPLY soft key.
RADAR
DISPLAY
RETURN
359.9 ˚R
11.70
nm
+
MODE
HD UP
SHIFT
HL
OFF
RINGS
HIGH
12/
H-UP
3nm
LP
319. 9
°
M
Radar display soft keys
3. Press the RINGS soft key to turn the rings on and select desired brilliance.
4. Press the RETURN soft key to finish.