Indices And Chart Enlargement - Furuno 1823C Operator's Manual

3.5.2

Indices and chart enlargement

When the [RANGE] key is operated, you will see several frames appear on the
chart. These frames are called indices and they show you what parts of the chart
can be enlarged in the current range.
When a chart cannot be displayed
A chart will not be displayed in the following conditions:
When the chart scale is too large or too small.
When scrolling the chart outside the indices.
When this happens, select proper chart scale.
Note: Indices can be turned on or off. For further details see "Chart border line"
on page 5-14 for FURUNO and NAVIONICS charts and page 5-16 for
C-MAP charts.
Sample chart (Japan), showing indices
3. PLOTTER OPERATION
3-11