NOAA Shoreline Website

A Guide to National Shoreline Data and Terms

NOAA Office of Coast Survey Shorelines

Purpose and Potential Applications: NOAA Electronic Navigational Chart (ENC) shoreline provides accurate shoreline data for public use. Other applications include cartography and boundary determination. These shorelines are not appropriate for navigation or to represent the legal shoreline, and should not be used for either purpose.

Originator(s): National Oceanic and Atmospheric Administration (NOAA), Office of Coast Survey

Abstract: NOAA Office of Coast Survey provides digital vector shoreline data extracted from large-scale NOAA nautical charts, or ENCs. The ENC shoreline is collected for navigable waters and accurately depicts the tidally influenced shoreline, including waterways and tidal creeks, since it corresponds to the black line seen on the nautical charts.


ENC: NOAA ENC Direct to GIS Web portal

Follow these steps to download the shoreline:

  1. Use the Zoom and Pan tools to navigate to an area of interest.
  2. Click the desired Data Extract button to begin the extraction process. A new window titled "Extract [Scale Band]" will appear.
  3. Select the area to obtain shoreline using one of the area polygons features. The area selected will be highlighted in blue.
  4. Select the following feature layers to extract to obtain shoreline
    • CoastlineL\[Scale_Band].Coastline_line
    • CoastlineL\[Scale_Band].Shoreline_Construction
  5. Select desired file format.
  6. Click [Extract] - A separate window will open allowing you to download the file to your computer as .zip file. Rename the file to something that you will remember.

Scale: Variable scale based on charts with 1:10,000 to 1:80,000 scales

Coverage: Continental U.S., including Alaska, the Great Lakes, Hawaii, Puerto Rico, the U.S. Virgin Islands, and other U.S. trust territories and Caribbean and Pacific islands.

Source Data: NOAA nautical charts

Spatial Reference: Geographic coordinate system (decimal degrees); Horizontal Datum – North American Datum of 1983 (NAD83)

Tidal Datums: Mean high water (MHW)

Data Format: ESRI shapefile, AutoCAD, and Google KML. Shorelines are not seamless and are distributed as line files that can be downloaded by a user-specified extent.

Accuracy: Nautical charts are updated as part of an ongoing process to create a cartographic representation of the best available data collected over the years, employing a variety of data collection technology and techniques and provided to the Office of Coast Survey using many scales, datums, and projections. Although technology has allowed for a drastic increase in positional accuracy, historical data have not been superseded for many areas. The data accuracy of the extracted vector products is checked against its source nautical chart only. It is in no way intended for navigational purposes.

Process Description: The NOAA ENC database has been built from a combination of charted information and 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 features on the paper chart. The objective is to use the most accurate information for features that are critical to the safety of navigation. NOAA uses a number of sources in compiling NOAA ENCs, including 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, and the largest scale paper chart of an area. ENC Direct to GIS data were created by transforming Approach and Harbor, Coastal, General, Overview, and NOAA ENC version 2 cells to ESRI's shapefile format using Safe Software's Feature Manipulation Engine. The ENC shoreline corresponds to the black line (approximate mean high water) seen on the nautical charts.

Point of Contact:

Coast Survey Development Laboratory
NOAA Office of Coast Survey
(301) 713-2645 x142

Other References: