Fugawi's ENC FAQ
Sample of an NOAA ENC as displayed in FUGAWI Marine
ENC
Raster
vs. Vector Charts
The structure and format of a vector-based
ENC is defined by the International Hydrographic Office S-57 standard,
which means that the ENC is in a non-proprietary, publicly available, and
internationally recognized format. The ENC contains information about the
location of each chart feature, as well as color, shape, depth, and the like.
This information is used by FUGAWI Marine ENC Charting Software to draw a
nautical chart display—one that has greatly enhanced functionality.
A raster chart, by
contrast, is a facsimile of a paper chart—that is, a picture of a chart
displayed on a computer screen. It is a file of information that can be thought
of as dots (or pixels). The raster file tells the computer what color to draw at
each pixel. Thus, the computer “knows” what color is there, but cannot
distinguish a black pixel that is part of a sounding from a black pixel that is
part of a dangerous wreck.
BSB Raster Chart (left) and vector-based NOAA ENC
chart (right), showing user-defined depth contours. FUGAWI Marine ENC users can
also switch off the display of soundings, lights or text, as well as change the
sounding measurements from meters to feet.
The ENC stores the feature, its latitude and longitude, and its
descriptive information. For example, when reading a ENC, FUGAWI Marine ENC
Software “knows” the depth of soundings, and can display it in feet or
meters depending on your preference. Furthermore, one can control the way FUGAWI
Marine ENC Software displays the data by switching
off the display of soundings, lights, or text as desired
2.
Who creates ENC charts?
The Office of Coast Survey (OCS) has
been involved in the development of the NOAA ENC chart suite to support the
marine transportation infrastructure and coastal management for a number of
years. Every NOAA ENC is in the International Hydrographic Office (IHO) S-57
international exchange format, and complies with the NOAA ENC Product
Specification. These NOAA ENCs, which support real-time navigation, are now
being released to the public at no cost.
NOAA ENC updates will provide automatic corrections for Notices to Mariners and
other changes. Once the updates have started, the NOAA ENC will be established
as an official navigational product, and the announcement will be made on: http://chartmaker.ncd.noaa.gov/mcd/enc/.
3. What are the current and
planned ENC coverage areas?
While the current dataset does not yet have
complete national coverage, the good news is that the catalog of charts is
continually growing. Better yet, the data and subsequent updates are available
free-of-charge from the NOAA website. Information about current NOAA ENC
coverage can be obtained from http://chartmaker.ncd.noaa.gov/mcd/enc/.
Currently, the regions indicated below have
substantial ENC coverage. All of the available charts in these regions are
included in the latest release of FUGAWI Marine ENC. Expanded coverage will be
available for download from within the FUGAWI Marine ENC software itself.
Areas with substantial ENC and IENC chart coverage
(as of October 2003)
6. What are
IENCs?
The U.S.
inland navigation system consists of 8,200 miles of rivers maintained by the
Corps of Engineers. The shallow draft waterways have many unique characteristics
and difficulties over coastal harbor and ocean navigation; river levels can
change by over 30 feet in a seasonal cycle, the navigation channel can shift
significantly within the river banks, and shifting yet ever present river
currents pose constant challenges in these confined waterways.
Following
recommendations by the National Transportation Safety Board, the National
Academy of Science and the American Waterways Operators, The United States
Congress directed the Corps of Engineers to develop and publish electronic
charts for the inland waterways. Development of Inland Electronic Navigation
Charts (IENCs) to cover the Mississippi River and tributaries thus began in 2001
with pilot projects on the Atchafalaya River in Louisiana and Lower Mississippi
River near Vicksburg, Mississippi. These projects involved the conversion of
inland waterway data, commonly used for river and channel maintenance, into the
international S-57 hydrographic data exchange. This highly structured data
format is now used for Corps IENCs.
Following the pilot project, development of initial IENCs to cover most of the
Mississippi and Ohio Rivers began in 2002. IENCs currently under development
are:
Many of
these IENCs are now available for FUGAWI Marine ENC. Eventually, all IENCs will
be maintained with updates of new or corrected data available for download as it
becomes available. However, until the update process is implemented, users
should be aware that the IENCs reflect best available information at the time
the data was collected.
4. Can the ENC and IENC
charts be used for GPS moving map navigation?
Yes, FUGAWI Marine ENC contains all of the FUGAWI
functionality (such as moving map navigation; GPS upload and download of
waypoints, routes, and tracks; and sending maps and charts to a PDA), as well as
the capability of displaying the vessel’s position on vector-based NOAA ENC
charts. Note that moving map navigation is not provided on FUGAWI View
ENC or on any of the no-charge viewers provided by NOAA or the ACOE--only on
FUGAWI Marine NEC, not on FUGAWI View ENC or on any of the no-charge viewers
provided by NOAA or the ACOE.
5. Can I query features on
an ENC Chart?
Yes, with FUGAWI marine ENC, you can query every feature on the vector
chart including lights, soundings, marks, channels, landmarks, etc. Further,
depths at the cursor position are indicated on the status bar.
6. Can I get ENC data for
non-U.S. waters?
Non-U.S. hydrographic offices and data producers around the world are also producing S-57 ENC data, although not all charts will be free-of-charge. The S-57 ENC Chart format has been ratified as the international standard for vector-based marine charts.
U.
S.-produced NIMA vector charts for foreign waters are only available to the
military or individuals with appropriate security clearance.
7. Where can I download new
NOAA ENC charts or IENC charts, or updates to existing data?
FUGAWI Marine ENC products include all the currently available NOAA ENC charts and the U.S. Army Corps of Engineers Inland Waterway Charts (IENCs) on CD-ROM as of the production date. Updates and expanded coverage will be available for download from directly within the software, or from www.fugawi.com.
8. I don't understand how to download and use ENC's; who should I call?
If
you will be using ENC's with Fugawi software, please visit their website,
contact them by e-mail at sales@fugawi.com,
or give them a call at 416-920-9300. If you are using the charts with some
other viewer, please contact the organization that provided them to
you--typically either NOAA or the Army Corps of Engineers. Waypoint is,
unfortunately, unable to offer technical support for free ENC products.