Blocks and other cadastre information the BOEM produces are generated in accordance with 30 Code of Federal Regulations (CFR) Part 556.8 Subpart A, (formerly Part 256.8 Subpart A (2010)) to support Federal land ownership and mineral resource management. Outer Continental Shelf (OCS) blocks serve as the legal definition for BOEM offshore boundary coordinates used to define small geographic areas within an Official Protraction Diagram (OPD) for leasing and administrative purposes. These polygons are clipped to the Submerged Land Act Boundary and Continental Shelf Boundaries. OCS blocks relate back to individual Official Protraction Diagrams (OPDs) and are not uniquely numbered. A block is uniquely described by the Protraction Number and Block Number (e.g., NK18-02, Block 6822). A full OCS block is 4800 x 4800 meters. Smaller, clipped aliquots are found along the Federal/State OCS boundary and along UTM zone borders. Only the most recently published paper or PDF versions of the OPDs or Supplemental Official Block Diagrams (SOBDs) should be used for official or legal purposes. These data were created in the applicable NAD83 UTM or NAD27 UTM/SPCS Projection and re-projected to GCS WGS84 (EPSG 4326) for management in BOEM's enterprise GIS. However, this service in this collection has been published in WGS 1984 Web Mercator Auxiliary Sphere (EPSG 3857). Because GIS projection and topology functions can change or generalize coordinates, these data are NOT an OFFICIAL record for the exact boundaries. These data are to be used for Cartographic purposes only and should not be used to calculate area.
Creator
Homeland Infrastructure Foundation Level Data HIFLD
Publisher
Pennsylvania Spatial Data Access (PASDA)
Date Issued
2025
Access Rights
Public
Format
File
Language
English
Date Added
November 16, 2025
Provenance Statement
The metadata for this resource was last retrieved from PASDA on 2025-11-16.