This chapter mainly shows you how to install the public keys, licenses and charts, manually update chart objects, and synchronize charts.
Official vector charts produced by National Hydrographic Offices are called ENC, Electronic Navigation Charts and delivered in S-57 format. An ENC chart is encrypted to prevent unauthorized use so the user needs a permit to
install the ENC. This permit could be loaded from a USB flash memory or CD-ROM.
Any new ENC must be loaded into the system. Some parts of the charts may be date dependent, i.e., they are visible after a set date or they are visible only for a limited period, etc.