Maritime Limits and Boundaries of United States of America

Downloadable Data

Downloadable Data

Downloadable Data

Downloadable Data

Project website

Date that the source FGDC record was last modified.

Converted from FGDC Content Standard for Digital Geospatial Metadata (version FGDC-STD-001-1998) using 'fgdc_to_inport_xml.pl' script. Contact Tyler Christensen (NOS) for details.

Partial upload of Spatial Info section only.

Replaced entire Lineage section to populate new Source Contribution field.

Partial upload of Positional Accuracy fields only.

Link to report.

US/Canada international boundary polyline was constructed using published coordinates from the US/Canada International Boundary Commission. The polyline was used as a source of this dataset. The boundary was merged with OCS' published maritime limits and maritime boundaries and further attributed | Source Geospatial Form: Text | Type of Source Media: online

Single dataset in WGS84 of digital state/regional maritime limits, created by merging published ESRI Shapefiles from NOAA's Office of Coast Survey website. Dataset was merged with the US/Canada international boundary to create the approved US maritime limits and boundaries dataset. | Source Geospatial Form: geodatabase feature class | Type of Source Media: online

Link to data source.

NOAA's Nautical charts are used to derive the US baseline, which incorporates the charted low-water line and closing lines across entrances to legal bays, rivers, and harbors. The most recent edition, largest scale nautical charts are used as a source of the baseline. | Source Geospatial Form: raster digital data | Type of Source Media: chart

The limits of the 12 nautical mile Territorial Sea, 24 nautical mile Contiguous Zone, and 200 nautical mile Exclusive Economic Zone as well as the maritime boundaries were published in vector digital data format on a state or region basis between 2002 and 2010. These previously published regional data were used as source for this dataset. They were compiled together and further attributed. | Source Geospatial Form: vector digital data | Type of Source Media: Vector digital data

Digital US maritime limits, maritime boundaries, and international boundaries were approved by the interagency US Baseline Committee. Dataset is continually revised based on changes to nautical charts or by special request. | Source Geospatial Form: vector digital data | Type of Source Media: vector digital data

Polylines of the US/Canada international boundary contructed from coordinates obtained from the IBC. Polylines combined with maritime limits to created the approved US maritime limits and boundaries dataset. | Source Geospatial Form: vector digital data | Type of Source Media: online

From 2002 to 2010, the interagency U.S. Baseline Committee re-evaluated the U.S. baseline and associated maritime limits as depicted on NOAA charts on a state or regional basis. As a result of this multiple year, iterative project, digital state/regional maritime limits, including the 200nm EEZ, were produced and published in ESRI Shapefile format on NOAA\x92s Office of Coast Survey website. To create a seamless, continuous maritime limits dataset, OCS did the following: 1) transformed the state/regional digital limits, in SHP format, from NAD83 to WGS84; 2) merged the WGS84 SHP files into a single dataset using ESRI ArcGIS and imported into a file geodatabase; 3) segmented the merged limits according to chart symbology groupings as well as feature type (e.g. maritime boundary, maritime limit, or land boundary) to more closely match NOAA charts; and 4) re-attributed the dataset | Source Produced: Merged Digital Maritime Limits and Maritime Boundaries

The coordinates of US/Canada international boundary were obtained from International Boundary Commission in NAD83 and saved into a text file. A point shapefile was created based on the text file in NAD83 and then transformed to WGS84. Polylines were constructed using the point shapefile. All polylines were constructed as rhumb lines, except the following three portions: 1) line segment from 43.631127N, 76.796687W to 43.631127N, 78.690388W; 2) line segment from 41.676561N, 82.397473W to 41.676561N, 82.679716W; 3) line segment in Gulf of Maine ruled by ICJ. These three portions were constructed as geodesic lines. The polylines were segmented according to the grouping of published coordinates on IBC website. New attributes were created and the polyline was attributed. | Source Produced: US/Canada international Boundary

US/Canada international boundaries generated in the second process step were imported into file geodatabase and merged with maritime limits generated in the first process step. Topology rules were established in the file geodatabase to detect overlapping, self-intersecting, and dangling polyline features. Any topological errors flagged by topology check were investigated and corrected when necessary. When a polyline feature spans across -/+180 longitude, ESRI clips the feature at the longitude, resulting in dangling polyline. Topology errors as a result of clipping at 180 longitude were marked as exception. Other topology errors were corrected. The dataset was exported as a shapefile. | Source Produced: US Baseline Committee Approved Maritime Limits and Boundaries

Maritime limits and boundaries are updated using the most recent edition, largest scale nautical charts. Updates are triggered by a new chart edition, or by a formal request to re-evaluate the baseline. Charts are used as a backdrop in the ESRI ArcMap environment to create vector shorelines and lines closing the entrances to legal bays, rivers, and harbors. These lines are imported to the Caris LOTS environment. The "Enevelope of Arcs from normal baselines" tool is applied to vector shorelines, and the "Envelope of Arcs from straight baselines" tool is applied to closing lines. As input to the tools, OCS selects the limit distance in nautical miles and designates minimum attributes for the baseline points. The tool generates the contributing baseline points and the boundary limit using a wagon-wheel filtering process of rolling a circle with a diameter specified by the limit distance and choosing the seaward-most points along the low water line. Previously approved limits are manually intersected and replaced with the revised limits to create seamless, revised limit lines. Caris generated EOA control lines, which display how baseline points contribute to particular arc segments of the limit line, are used to inform the manual intersect and replace function. The final dataset is exported from Caris to a shapefile in WGS84, and attributed in the ESRI ArcMap environment.