Vector (S57) Charts; Introduction To S57 Charts - Furuno FAR-3210 Operator's Manual

9.

VECTOR (S57) CHARTS

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.
9.1

Introduction to S57 Charts

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 DVD ROMs, CD ROMs and USB flash
memory or electronically through from LAN (Local Area Network) in which it could
have arrived in DVD ROMs, CD ROMs or USB flash memories. Such material can
contain only basic cells, cells and updates or only updates. The electronic chart sys-
tem contains as standard the software required to access a medium.
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.
9-1