Furuno FCR-28x9 Manual De Usuario

Theoretically a chart can be coded for use on a computer as a vector chart. Vector-
coded charts are coded using a variety of techniques. One technique is called S57ed3 
and it has been chosen by IMO as the only alternative for SOLAS compliant electronic 
charts. If an S57ed3-coded chart is published by a government-authorized Hydro-
graphic Office, then it is called "ENC". You can read more about ENC and related legal 
issues in this chapter. Hereafter, all references to vector chart material are referred to 
as "S57 charts" regardless of their source.

Sometimes you may wish to manually add Notices to Mariners or Navtex warnings into 
your S57 charts. This is called "manual updates". Also, manual updates are valid for 
all scales so that you don't need to repeat them for charts published in different scales 
from the same area.

An ENC chart is encrypted to prevent unauthorized use so the user needs a permit to 
view the ENC. This permit could be entered manually from the Control Unit, loaded 
from a USB flash memory.

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. In the electronic chart system, you control all date-dependent objects with 
Display date and Approved Until dates. In the paper chart world, the Preliminary and 
Temporary Notices to Mariners represent the date dependency described above for 
S57 charts.

An important part of ENCs are the updates. Hydrographic Offices can issue two kinds 
of updates:

1. Incremental updates, which are small additions to original base cells.
2. Reissues and new editions, which are complete replacements of previous base 

cells and their updates.

All updates are date stamped and they may also contain date-dependent parts. You 
control usage of updates in the electronic chart system from Display date and Ap-
proved Until dates. Using Display date and Approved Until dates, you can view your 
charts correctly drawn on any date in the past or in the future.

Chart material will be stored in media such as CD ROMs and USB flash memory or 
electronically through from LAN (Local Area Network) in which it could have arrived in 
CD ROMs or USB memories. Such material can contain only basic cells, cells and up-
dates or only updates. The electronic chart system contains as standard the software 
required to access CD ROMs or USB flash memory. 

Each S57 chart may contain additional links to textual descriptions or pictures, besides 
the chart itself. Typically additional textual descriptions and pictures contain important 
sailing directions, tidal tables and other traditional paper chart features that do not 
have any other method to be included into the S57 chart. This system copies these 
textual descriptions and pictures into its SSD so the user may cursor-pick them for 
viewing purposes.