Optional use of ECDIS
visually, cannot be interrogated for e.g. automatic route checking or hazard warnings;
however some of these limitations can be minimised by manual user input to the ECDIS.
RNC data format and production
RNCs are normally produced by digitally scanning the stable colour bases used in the
multi-colour printing process. Unlike ENCs there is not a single accepted format for
RNCs. The main formats are
• BSB (used by USA, Canada, Cuba and Argentina), and
• HCRF (used by UK, Australia and New Zealand).
RNC Visualisation
• RNCs are designed to be displayed at the same resolution as that which they are
provided. Excessive zooming in or out of the same image seriously degrades the RNC
image. RCDS allows charts of appropriate scale to be displayed; when the user wants
to zoom in then a larger scale chart will be displayed and similarly on zooming out a
smaller scale chart will be used;
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