Operator's Manual

12. NAVIGATION TOOLS
12-5
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 Ring interval (nm) Chart scale Ring interval (nm)
1:1,000 0.025 1:100,000 2.0
1:2,000 0.05 1:200,000 4.0
1:5,000 0.10 1:500,000 8.0
1:10,000 0.25 1:1,000,000 16.0
1:20,000 0.5 1:2,000,000 20.0
1:50,000 1.0
Range
ring