Introduction to Electronic Chart Navigation: With an Annotated ECDIS Chart No. 1

by David Burch 

There are two types of electronic charts: raster navigational charts (RNC) and electronic navigational charts (ENC). RNC are exact copies of paper charts and their use underway comes naturally to navigators accustomed to paper charts. All traditional paper charts, however, and their RNC are being discontinued by NOAA. Many are gone already and all will be gone in a year or so.