Check Area; Ring - Furuno FMD-3100 Operator's Manual

12.3

Check Area

Check area sets the area ahead and around own ship for which to check for safe nav-
igation. See section 8.2 for how to activate own ship check.
12.4

Ring

The range rings are the concentric set of rings on the ECDIS display. They provide an
estimation of the range to an object. You can turn them on or off from the [Ring] page.
The interval between rings changes with the chart scale as shown in the table below.
Chart scale
1:1,000
1:2,000
1:5,000
1:10,000
1:20,000
1:50,000
Range
ring
Ring interval (nm)
0.025
0.05
0.10
0.25
0.5
1.0
12. NAVIGATION TOOLS
Chart scale Ring interval (nm)
1:100,000
1:200,000
1:500,000
1:1,000,000
1:2,000,000
2.0
4.0
8.0
16.0
20.0
12-5