Creating a GIS from NOAA electronic navigational charts

NOAA\´s Electronic Navigational Charts (NOAA ENC®s) have been developed to support the marine transportation infrastructure and coastal management. The NOAA ENCs are in S-57, a data standard developed by the International Hydrographic Organization (IHO) to be used for the exchange of digital hydrographic data. NOAA ENCs can be incorporated into geographic information systems (GIS) extending NOAA ENCs use and accessibility. However, many GIS\´s, cannot read an ENCs native S-57 format. To address this problem, "NOAA\´s ENC Direct to GIS" ( ENC Direct) Web portal provides comprehensive access to all available large scale NOAA ENC data in a variety of GIS/CAD formats for non-navigational purposes using Internet mapping service technology. Nautical chart features contained within an NOAA ENC provide a detailed representation of the U.S. coastal and marine environment. This data includes coastal topography, bathymetry, landmarks, geographic place names and marine boundaries. Features in an NOAA ENC are limited in that they only represent the geographic region that is depicted in that particular NOAA ENC. By aggregating nautical features from NOAA ENCs in the creation of GIS data, a contiguous depiction of the U.S coastal and marine environment is achieved. In the Internet mapping service, marine and coastal features are represented as layers organized into categorical groups. Using the Internet mapping service\´s GIS tools, ENC Direct layers can be explored. Because the data is not certified for navigation, symbolization of ENC Direct data is generalized. Geographic place name labels also provide orientation. ENC Direct allows users to specify output format, coordinate system and the spatial extent of the data they wish to download through query and selection tools.