Pacific Cadastral Data

Geographic Information System (GIS) Data and Maps

The Geospatial Services Division performs mathematical offshore boundary location computations and prepares Official Protraction Diagrams (OPDs), and Supplemental Official OCS Block Diagrams (SOBDs) depicting OCS Block information, the Submerged Lands Act Boundary (aka - State Seaward Boundary), Limit of "8(g) Zone", the Continental Shelf Boundary (CSB), which marks the limit of U.S. jurisdiction for offshore mineral development, and corresponding area measurements. The analytical procedures employed and the computer programs utilized to perform various offshore boundary geometric computations are described in OCS Report MMS 99-0006. 

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OPD Images

A standard OPD is 1 degree in latitude by 2 degrees in longitude (at lower latitudes: 0 - 48 degrees). At higher latitudes (48 - 75 degrees) such as Alaska and northern Washington, OPDs are 3 degrees wide. OPD limits usually approximate the standard 1:250,000 scale U.S. Geological Survey topographic map series. The OPDs are numbered using the United Nations International Map of the World Numbering System. OPD names usually coincide with standard topographic sheet names when diagrams include land areas. OPD sheet names relate to land features, or to hydrographic features contained within the limits of the diagram. Shoreline planimetric detail is shown when it falls within the limits of a diagram. Older OPDs were prepared on mylar with manual cartographic methods and then scanned into Adobe .pdf files. Newer OPDs were prepared electronically and converted to Adobe .pdf files.

NOTE: OPDs offshore of Oregon and Washington that show the Submerged Lands Act and Section 8(g) Zone boundaries do not reflect post-2010 shoreline changes.  The Submerged Lands Act and 8(g) Zone boundaries offshore of California were permanently immobilized by the U.S. Supreme Court on December 15, 2014.

SOBD Images

A Supplemental Official OCS Block Diagram (SOBD) is prepared for each block intersected by an offshore boundary (Submerged Lands Act Boundary, Limit of "8(g) Zone", National Marine Sanctuaries, etc.). Note that not all OPDs contain such boundaries, therefore not all OPDs have SOBDs associated with them. All the SOBDs for a given OPD are zipped into a single file for downloading. The zip files will contain the most recent version, but older historic versions may also be included for reference. For the purpose of future Lease Sales always be sure to use the most recent version.

NOTE: SOBDs offshore of Oregon and Washington do not reflect post-2010 shoreline changes.  The Submerged Lands Act and 8(g) Zone boundaries offshore of California were permanently immobilized by the U.S. Supreme Court on December 15, 2014.

CBD Images

Composite Block Diagrams (CBDs) show NAD 27 lease information portrayed on the NAD 83 cadastre. Not all OPDs have CBDs associated with them.

• NI10-06-CBD.zip
• NI11-04-CBD.zip
• NI11-07-CBD.zip 

GIS Files

The various boundaries can be viewed in BOEM’s GeoSEAS ArcGIS Online (AGOL) as services. They are also offered as ESRI ArcGIS shapefiles. Shapefiles can be viewed with ArcGIS or a variety of other GIS systems. The shapefiles have been zipped using WinZip.

Note: The precise coordinates of a GIS file can be altered slightly by various GIS functions. For that reason, these GIS files are not an Official Record for BOEM offshore boundaries. Only the coordinates shown on Official OPDs, CBDs, and SOBDs constitute an Official Record for offshore coordinate values.

All coordinates are in NAD 83. Pacific Region leases and cadastre data from before 1994 were mapped using the North American Datum of 1927 (NAD 27). These new NAD 83 files do not represent a conversion, but rather a complete re-grid. For further details, see Project Plan for Implementing NAD 83 in the Bureau of Ocean Energy Management:

• Part I: Responsibilities and Timeframes
• Part II: Technical Aspects of Implementation
• Summary Status Report

 Planning Area Acreage Statistics

Offshore Marine Cadastre (OMC)

The Offshore Marine Cadastre (OMC) Navigator is a national viewer showing Protractions, Blocks, Aliquots, and Boundaries covering the Outer Continental Shelf (OCS). These are units of area measurement that officially describe the OCS and demarcate areas that could be leased for energy in accordance with 30 CFR 550.400, 30 CFR 585.205, and 30 CFR 581.15. The main purpose of the viewer is to provide PDF links to BOEM’s Official Mapping Products known as Official Protraction Diagram Index Maps, Official Protraction Diagrams (OPDs), Official Protraction Aliquots Diagrams (OPADs), and Supplemental Official Block Diagrams (SOBDs).

Additional Pacific Data Sources

•  Pacific OCS Lease Information