Sperry Marine Visionmaster FT ECDIS, Руководство пользователя

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ECDIS User Guide Charts
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The largest scale chart at the centre of the display is overscaled, in
most cases the display is covered by several charts.
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An overscaled non-vector (e.g. raster) chart is displayed.
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An overscaled vector chart from the most detailed usage level is
displayed.
A chart is considered to be overscaled if the scale ratio of the display is
larger than the compilation scale of the chart. For example, the overscale
prompt will be shown if the scale ratio is set to 1:20,000 and the displayed
chart at screen centre has a compilation scale of 1:25,000. The scale of
each chart can be viewed in the Chart Index window, see Tools.
Display Overscale Pattern
The overscale pattern is displayed over charts if the
scale ratio of the display is more than double the
compilation scale of any charts in the display. For
example, if the compilation scale of the displayed chart
is 1:75,000 and the scale ratio is set to 1:30,000 or less.
The overscale pattern is a series of closely aligned
dotted vertical lines across the whole of the chart
display.
Larger Scale Available Prompt
The Larger Scale Chart Available at Ship prompt is shown when the
largest scale chart under the ships position, considering ALL enabled chart
databases, is not displayed.
Chart Safety Information
Chart data suppliers such as UKHO may provide additional safety-related
information about supplied ENC chart sets. This information comes in the
form of a ReadMe.txt file which is accessed from the SevenCs
ChartHandler screen.
Chart One Presentation Library
The Chart One Presentation Library contains an index of chart symbols, as
used on vector charts, see Chart 1.