Answer - In short, no. The NOAA ENC® uses the international standard format for vector electronic charts, the International Hydrographic Organization "Transfer Standard for Digital Hydrographic Data, Special Publication S-57." The file format used by the S-57 standard is ISO/IEC 8211, "Information processing - Specification for a data descriptive file for information interchange.

Answer - All NOAA ENC®s that are considered "completed" are up to date for the current Notices to Mariners. They will also have any new chart information included within a few weeks of the information's arrival at NOAA.

Answer - Marine navigation, route planning, and GIS applications are just some the uses for the data as a background display. USCG already uses NOAA ENC® in several Vessel Traffic Systems (VTS) to monitor ship movements in rivers, harbor, and bays in the U.S. Since NOAA ENC® is a vector product, categories of data may be individually selected or queried. Because of this data flexibility, NOAA ENC® is a powerful database supporting various marine and GIS applications.

Answer - Besides the CATALOG file explained above, there is a README.TXT file included that lists all of the NOAA ENC®s with their corresponding paper/raster chart number, title and other information. Each NOAA ENC® may have ancillary files associated with it. These may be text files that are analogous to chart notes on the paper chart or possibly information from the Coast Pilot. There also may be picture files such as .tif or .

Answer - Creation of the database for producing NOAA ENC®s takes time and resources. We currently project that the initial coverage of major commercial ports will be completed by 2002. It is anticipated, however, that NOAA ENC® data will be made publicly available before the entire coverage is complete. We plan to have data available starting in 2001 with updating soon to follow.

Answer - NOAA ENC®s and RNCs will eventually replace paper charts for vessels using electronic navigation. NOAA will continue to produce paper charts for those users who do not choose to use electronic navigation. NOAA ENC®s and ECS are the greatest advancement in maritime safety since the introduction of radar to ships.

Answer - The NOAA NOAA ENC® program is building the NOAA ENC® production database from a combination of charted information as well as original "source" information. NOAA has compiled critical features such as channel limits, aids to navigation and obstructions from the original documents that were used to put the feature on the paper chart.

Answer - NOAA uses a number of sources in compiling NOAA ENC®s. These include: U.S. Army Corps of Engineers surveys, drawings and permits, U.S. Coast Guard Local Notices to Mariners, National Imagery and Mapping Agency Notices to Mariners, NOAA hydrographic surveys, the largest scale paper chart of the area, as well as other source material that comes in to NOAA from a variety of public and private sources.

Answer - Approximately 100 NOAA ENC®s are available for evaluation, familiarization, testing and software development from the Coast Survey Website (nauticalcharts.noaa.gov).

Answer - This is yet to be determined. In paper chart production, new editions are driven by the amount of new information to be applied to the chart as well as how many copies are in stock for use. Neither of these considerations really apply to the NOAA ENC®, so new NOAA ENC® editions may be synchronized to the paper chart cycle or may be on a set schedule, e.g., annually released.

Answer - The area covered by an NOAA ENC® is referred to as a "cell." At present, each NOAA ENC® corresponds to the largest scale paper chart in a given area. As the NOAA ENC® begins to contain more detail and the file sizes get larger, it may become necessary to split the cells into smaller areas.

Answer - Incorporating digital chart data with a continuous GPS signal for automated vessel positioning enhances safety of navigation. Users can selectively display only the information desired while the computer can continue to process all the information for safety of navigation. Many marine mishaps are due to human error. Vector chart data with proper software applications will enhance safe navigation and provide the mariner with advance electronic warnings of unforeseen dangers.

Answer - NOAA ENC®s will be updated with new source material and Notices to Mariners (both Local and NIMA). The NOAA ENC® production system will be able to convert any new source materials such as hydrographic surveys, Notices to Mariners, etc. for inclusion in the NOAA ENC® database.

Answer - The NOAA ENC® file name format is specified in the IHO S-57 standard. The first two characters, US, indicate that the U.S. Office of Coast Survey, NOAA, produced the NOAA ENC®. The third character indicates the "navigational purpose" of the NOAA ENC® as defined in S-57, a rough indicator of the scale of the NOAA ENC®: 1-overview; 2-general; 3-coastal; 4-approach; 5-harbor; 6-berthing. The remaining characters left of the dot are defined by Coast Survey.

Answer - NOAA ENC®s will be available for download from the Coast Survey Website (nauticalcharts.noaa.gov).

Answer - The NOAA NOAA ENC® contains most of the features currently shown on the corresponding paper chart. The detailed road networks and depictions of buildings in urban areas has been replaced with an "urban area" that is displayed as a tinted area with the associated place name.

Answer - Coast Survey will not provide NOAA ENC®s on any hard media, they will be only available from the Government at the Coast Survey Website (nauticalcharts.noaa.gov). However, private companies may make NOAA NOAA ENC®s available on products that are available on hard media.

Answer - Display of and NOAA ENC® is dependent on navigation software such as an ECDIS. However, the NOAA ENC® is not dependent on unique operating systems or navigation software. Since it is provided in an international, publicly available standard format, any software company that wants to support NOAA ENC® data can implement that capability without restricting the software to a proprietary format or provider.

Answer - Yes. A number of commercially available systems use NOAA ENC® data. These include both "type- approved" ECDIS software as well as ECS packages.

Answer - Yes. NOAA plans to provide updates for the NOAA ENC® similar to the updates currently provided for the raster chart. These will include all Local Notices to Mariners corrections.

Answer - This depends on the customer electronic navigation systems - nothing in the data precludes display of the data from ship's radar screen or, when adopted, Automatic Identification System (AIS) symbology.

Answer - The date shown on the NOAA ENC® download page is the date that the compressed NOAA ENC® archive was last modified. This usually means that a new, updated cell replaced the NOAA ENC® cell file. It may also mean that one or more of the supporting text or picture files was modified. Users should always make sure that they are using the latest version of the NOAA ENC® and its supporting files.

ANSWER: They both have strengths and weaknesses. Vector data allow displays to be decluttered and support automated alarms based on the data itself. Raster data provides most of the ECDIS functionality but are far easier to produce and are more widely available. However, this is a misleading question. The real questions are: Does RCDS provide the tools for a mariner to safely navigate? (Yes, tests at sea so indicate.) Does it enhance safety of over the paper chart? (Yes, a survey of U.S.

ANSWER: Software can remap the RNC's colors and their brightness to any other colors and brightness available on the host computer. Thus dusk, twilight and nighttime colors can be specified. National hydrographic offices providing RNC's should specify a pallet for their charts which is most suitable for those different conditions. ANSWER: No.

Answer - In short, yes they do. Every NOAA ENC® starts with a file header that has various information, metadata, about that particular NOAA ENC®. The header has a number of "subfields," each of which has information about a particular aspect of the NOAA ENC®. One subfield is the edition number, which is a sequential number that works just like the edition number on a paper chart.

Answer - NOAA ENC Direct to GIS data is in a format that is not certified for navigation. The data is derived from the official NOAA ENCs through GIS conversion software.

Answer - Click the "Extract" button from the toolbar menu to bring up the Data Order Form. For detailed instructions on how to use the Data Order Form click here (Data order form Link)

Answer - No, NOAA ENC Direct to GIS is not certified for navigation. You can download NOAA ENCs for navigation at http://nauticalcharts.noaa.gov/mcd/enc/index.htm.

Answer - The S-57 object catalog can be used to look up NOAA ENC Direct to GIS layer and attribute definitions. A free, on-line S-57 Object Catalog is available at http://www.s-57.com. This service is for informational purposes only and does not constitute an endorsement by the U.S. Government.

Answer - The data layers have been created from merging S-57 object classes from all large scale NOAA ENCs into seamless layers. For example, the Approach_Harbor coastline layer is a composite of the S-57 object class COALNE from all current Approach and Harbor ENCs.