This file is based on the Geospatial Services Division's Official Protraction Diagram (OPD) and Leasing Maps (LM). Each offshore area is defined by an API Number corresponding to those in the API Bulletin Number D12A. OPDs are numbered using the United Nations International Map of the World Numbering System, and are generally named for land or hydrographic features contained within the limits of the diagram. OPDs and LMs are mapping products produced and used by the BOEM to delimit areas available for potential offshore mineral leases, determine the State/Federal offshore boundaries, and determine the limits of revenue sharing and other boundaries to be considered for leasing offshore waters. This dataset shows only the outline of the maps that are available from BOEM.Only the most recently published paper or pdf versions of the OPDs or LMs should be used for official or legal purposes. The pdf maps can be found by going to the following link and selecting the appropriate region of interest: https://www.boem.gov/Official-Protraction-Diagrams/

Both OPDs and LMs are further subdivided into individual Outer Continental Shelf(OCS) blocks which are available as a separate layer. Some OCS blocks that also contain other boundary information are known as Supplemental Official Block Diagrams (SOBDs.)

Further information on the historic development of OPD's can be found in OCS Report BOEM 99-0006: Boundary Development on the Outer Continental Shelf:

https://www.boem.gov/BOEM-Newsroom/Library/Publications/1999/99-0006-pdf.aspx

Because GIS projection and topology functions can change or generalize coordinates, these GIS files are considered to be approximate and are NOT an OFFICIAL record for the exact block coordinates or areas. The Official Protraction Diagrams (OPDs) and Leasing Maps (LMs) and Supplemental Official Block Diagrams (SOBDs) serve as the legal definition for BOEM offshore boundary coordinates.