FGDC Marine Boundary Working Group

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FGDC Marine Boundary Working Group

U.S. Marine Cadastre

Multipurpose Marine Cadastre

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FGDC Marine Boundary Working Group

U.S. Marine Cadastre - Maritime Zones

International Maritime Boundaries • Baseline • Territorial Sea • Exclusive Economic Zone • Continental Shelf Limit • U.S. Contiguous Zone

International Maritime Boundaries
Description: The U.S. continental shelf and exclusive economic zone (EEZ) claims cover approximately three million square miles of ocean space. Overlapping boundaries with other nations exist in 25 situations. International maritime boundaries are those agreed upon by one or more countries to resolve these overlapping claim issues.
Primary Agency: Minerals Management Service (MMS) & National Oceanic and Atmospheric Administration (NOAA), National Ocean Service, Office of the Coast Survey.
Spatial Extent: Dependent on boundary.
Description: The following notices have been published that define U.S. maritime boundaries and fishery conservation zones: Public Notice 506, Federal Register, Vol. 41, No. 214, November 4, 1976, 48619-20; Public Notice 526, Federal Register, Vol. 42, No. 44, March 7, 1977, 12937-40; Public Notice 544, Federal Register, Vol. 42, No. 92, May 12, 1977, 24134; Public Notice 4710-01, Federal Register, Vol. 43, No. 7, January 11, 1978, 1658; Public Notice 585, Federal Register, Vol. 43, No. 7, January 11, 1978, 1659; Public Notice 910, Federal Register, Vol. 49, No. 155, August 9, 1984, 31973. (Department of Defense (DOD) document 2005.1-M).
Official Depiction: NOAA nautical charts.
Known Digital Data Source: NOAA Office of Coast Survey, accessible on-line at http://chartmaker.ncd.noaa.gov/csdl/eez.htm
Original Metadata: None currently available on-line
Notes: Sometimes the U.S. recognizes a maritime boundary that is not recognized by a neighboring country (e.g., Cuba). Negotiations often carry on for many years before a bilateral treaty is signed (e.g., U.S./Canada Boundary in the Gulf of Maine).
Issues: There appears to be a difference between the NOAA U.S. exclusive economic zone coverage and the MMS coverage. There are several places where the difference between these two coverages is approximately .001 decimal degrees (about 400 meters). The maritime boundary points of the EEZ are published in the Federal Register to the nearest second (.00027 decimal degrees), although, this does not imply precision (Loy 1999). Several references to ambulatory points are made (e.g., "the international maritime boundary in the Gulf of Mexico shall begin at the center of the mouth of the Rio Grande, wherever it may be located").

Baseline
Description: The line from which maritime zones are measured. The normal baseline for measuring the territorial sea (TS), contiguous zone (CZ), exclusive economic zone (EEZ) and continental shelf is the low-water line along the coast.
Primary Agency: National Oceanic and Atmospheric Administration (NOAA), National Ocean Service, Office of Coast Survey.
Spatial Extent: Average of lower low tides (i.e., ordinary low water), or closing lines (i.e., bays and rivers), as depicted on the largest scale NOAA nautical chart for a region.
Relevant References: Presidential Proclamation No. 5928. 3 C.F.R. Sect. 547 (1989). The 1958 Convention on the Territorial Sea and the Contiguous Zone arts. 3-13; the 1982 Law of the Sea Convention (LOSC) arts. 5-11, 13-14. The U.S. is not a party to the LOSC but recognizes it as reflecting customary international law, as provided in Presidential Proclamation 5030.
Official Depiction: Baseline "marked large-scale charts officially recognized by the coastal States" (LOSC art. 5). "State" refers to nation-state or sovereign state and, in the U.S., official charts are NOAA nautical charts.
Known Digital Data Source: None available for web site at this time. The data is currently under official review and will be released at a future date.
Notes: [Actual] Baselines are ambulatory and subject to changes as the shoreline accretes and erodes. The normal baseline from which the maritime zones are charted may be synonymous with the coastline under the Submerged Lands Act (SLA). See specific laws and notices the application of various laws that use baselines and boundaries.
Issues: See M. Reed, Vol. 3 Shore and Sea Boundaries; and A. Shalowitz Vols. 1&2 Shore and Sea Boundaries.

[U.S.] Territorial Sea
Description: The U.S. asserts sovereignty over its lands, airspace, seabed and water from the baseline to the 12-nautical-mile territorial sea boundary (also termed the marginal sea). Prior to the Presidential Proclamation, the territorial sea designation was 3 nautical miles and was coextensive with boundaries for states under the Submerged Lands Act (SLA).
Primary Agency: National Oceanic and Atmospheric Administration (NOAA), National Ocean Service, Office of Coast Survey.
Spatial extent: 12 nautical miles from the baseline.
Description: : Presidential Proclamation of December 27, 1988, No. 5928 (3 C.F.R. 547 (1989)), consistent with international law as described in the United Nations Convention on the Law of the Sea (UNCLOS). Part II, art. 2.
Official Depiction: NOAA nautical charts (Loy 1999). 33 U.S.C 883a-i.
Known Digital Data Source: : Known Digital Data Source: Available on-line at nauticalcharts.noaa.gov/csdl/mbound.htm
Original Metadata (unofficial, SE Atlantic): Available on-line at www.nauticalcharts.noaa.gov/csdl/mbound.htm.
Notes: This boundary, like the baseline from which it is measured, may be ambulatory. Although the official chart may provide a presumption on that line's location, that does not preclude the submission of extrinsic evidence to prove the actual line defined through methods employed by the official charting agency, NOAA.
Issues: Offshore boundary lines are measured along an arc over the earth's ellipsoidal surface (chord length); therefore, arc distance varies with latitude and azimuth corresponding to variations in the radius of the earth's surface. As a result, the arc length must be computed (in three-dimensional space) separately for each stretch of coastline, even though the projection distance remains unchanged (Ball 1997). Many boundaries have been created using a buffer function in a geographic information system. This process does not take into account chord length or distortion due to projection and often may result in an inaccurate representation of the "envelope of arcs." Accordingly, the GIS boundary data may not accurately reflect the official or actual boundary.

Exclusive Economic Zone
Description: The zone or area beyond and adjacent to the territorial sea. In this area, the U.S., like other coastal nations, has sovereign rights and exclusive jurisdiction to protect and manage its natural resources, including any economic development. The seaward limit of the EEZ is generally 200 nautical miles from the baseline. The U.S. does not have sovereignty in the EEZ as it does in its territory. Foreign vessels and nationals maintain the high seas freedoms or rights of navigation and overflight in the EEZ, as well as the right to lay and maintain submarine cables and pipelines. However, such rights are still subject to regulation by the U.S. in accordance with international law, including UNCLOS.
Primary Agency: National Oceanic and Atmospheric Administration (NOAA), National Ocean Service, Office of Coast Survey.
Spatial extent: The EEZ is the maritime zone adjacent to the territorial sea and generally extends out to 200 nautical miles from the baseline, unless it would extend into or overlap with a 200 EEZ of an opposite or adjacent nation. In such cases, the states should achieve an equitable solution through an agreement on the delimitation of their respective EEZs. The 200 nm outer boundary line, like the baseline from which it is measured, is ambulatory.
Description: Presidential Proclamation 5030, March 10, 1983 (3 C.F.R. 22); the Magnuson Act, 16 U.S.C. § 1802 (11) (definition of EEZ); 60 F.R. 43825 (Aug. 23, 1995)(public notice of the limits of the U.S. EEZ - supercedes all previous public notices of any fishery conservation zone or EEZ)
Official Depiction: NOAA nautical charts.
Known Digital Data Source: Information about these data are available on-line from NOAA's Office of Coast Survey at http://chartmaker.ncd.noaa.gov/csdl/eez.htm
Original Metadata: None currently available on-line
Notes: Data and documentation inconsistencies exist.
Issues: Offshore boundary lines are measured along an arc over the earth's ellipsoidal surface (chord length); therefore, arc distance varies with latitude and azimuth corresponding to variations in the radius of the earth's surface. As a result, the arc length must be computed (in three-dimensional space) separately for each stretch of coastline, even though the projection distance remains unchanged (Ball 1997). Many boundaries have been created using a buffer function in a geographic information system. This process does not take into account chord length or distortion due to projection and often may result in an inaccurate representation of the "envelope of arcs." Accordingly, the GIS boundary data may not accurately reflect the official or actual boundary.

U.S. Continental Shelf Limit
Description: Article 76 of the United Nations Convention on the Law of the Sea (UNCLOS) provides a definition and a detailed formula for determining the limit of the continental shelf beyond 200 nautical miles. Consistent with Article 76 of UNCLOS and the 1958 Convention on the Continental Shelf, the U.S. continental shelf is comprised of the sea-bed and subsoil of the submarine areas that extend beyond its territorial sea throughout the natural prolongation of its land territory to the outer edge of the continental margin, including that portion beyond 200 nautical miles from the baseline. Under international law, the continental shelf is defined to include the sea-bed and subsoil beyond the continental margin out to a distance of 200 nautical miles from the baseline. The U.S. has sovereign rights and exclusive jurisdiction over the exploration and exploitation of the continental shelf.
Primary Agency: Minerals Management Service, as requested by the Department of State, Memorandum of Understanding dated October 5, 1994.
Spatial extent: 100 fathom isobath as outer limit (Presidential Proclamation, No. 2667, 1945). This limit shall not exceed either 350 nautical miles from the baseline from which the breadth of the territorial sea is measured or 100 nautical miles from the 2,500 meter isobath (Thormahlen 1999a).
Description: 1958 Convention on the Continental Shelf, UNCLOS, Art. 76; Presidential Proclamation No. 2667, 1945, 3 CFR 67; Outer Continental Shelf Lands Act of 1953, 43 USCS 1331 (a) (2001) Definition: The term "outer Continental Shelf" means all submerged lands lying seaward and outside of the area of lands beneath navigable waters as defined in section 2 of the Submerged Lands Act (Public Law 31, Eighty-third Congress, first session) 43 USCS @ 1301] , and of which the subsoil and seabed appertain to the United States and are subject to its jurisdiction and control)
Official Depiction: Delimitation not charted yet.
Known Digital Data Source: A nonofficial boundary, produced by the Florida Marine Research Institute, is available on-line at http://www.floridamarine.org/
Original Metadata: The nonofficial metadata records for SE Atlantic region are available on-line at www.floridamarine.org/
Notes: 100 fathom isobath was outer limit (Presidential Proclamation, No. 2667, 1945). Under Article 1 of the 1958 Convention on the Continental Shelf, the outer limit of the continental shelf is subject to change in light of technological advances. It defines the outer limit as extending "to a depth of 200 meters or, beyond that limit, to where the depth of the superjacent waters admits of the exploitation of the natural resources of the said areas." Under Article 76 of UNCLOS, the limit of the continental shelf shall not exceed either 350 nautical miles from the baseline or 100 nautical miles from the 2,500 meter isobath (Thormahlen1999a).
Issues: No vertical datum or quantitative description is specified.

U.S. Contiguous Zone
Description: The U.S. contiguous zone is a belt of sea, adjacent to the territorial sea, over which the U.S. exercises the control necessary to prevent infringement of its customs, fiscal, immigration, or sanitary laws. The U.S. may also prescribe and enforce laws against foreign flagged vessels and nationals to protect the underwater cultural heritage (UCH) to the outer boundary of that zone consistent with international law, including Article 303 of UNCLOS. Within the contiguous zone, ships and aircraft of foreign countries maintain the high seas rights of navigation and overflight consistent with international law. From 1988 to 1999, the U.S. contiguous zone was co-terminus with the U.S. 12 nm territorial sea.
Primary Agency: National Oceanic and Atmospheric Administration (NOAA), National Ocean Service, Office of the Coast Survey.
Spatial extent: 12 to 24-nautical-miles from the baseline.
Description: : Presidential Proclamation No. 7219 of September 2, 1999, [64 F.R. 48,701 get CFR cite] in accordance with international law, including UNCLOS, art. 33.
Official Depiction: None at this time. In the future, the contiguous zone may appear on NOAA nautical charts.
Known Digital Data Source: Nonofficial southeast boundary, produced by NOAA's Coastal Services Center, is available on-line at nauticalcharts.noaa.gov/csdl/mbound.htm
Original Metadata: None.
Notes: Boundary, like the baseline from which it is measured from, may be ambulatory.
Issues: Offshore boundary lines are measured along an arc over the earth's ellipsoidal surface (chord length); therefore, arc distance varies with latitude and azimuth corresponding to variations in the radius of the earth's surface. As a result, the arc length must be computed (in three-dimensional space) separately for each stretch of coastline, even though the projection distance remains unchanged (Ball 1997). Many boundaries have been created using a buffer function in a geographic information system. This process does not take into account chord length or distortion due to projection and often may result in an inaccurate representation of the "envelope of arcs." Accordingly, the GIS boundary data may not accurately reflect the official or actual boundary.