This data set contains baseline tangent lines in ArcGIS shapefile format for the BOEMRE Atlantic Region. Baseline tangent lines are typically bay or river closing lines used by the BOEMRE to calculate the Submerged Lands Act (SLA) boundary, the Limit of '8(g) Zone', and other offshore boundary lines. These tangent lines would project straight line segments in any projected line, while baseline points would project circular arc segments to the projected boundary. A second file containing baseline points is also available. Additional details are available from: http://www.boemre.gov/itd/pubs/1999/99-0006.PDF 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 baseline coordinates. The Official Protraction Diagrams (OPDs) and Supplemental Official Block Diagrams (SOBDs) serve as the legal definition for BOEMRE offshore boundary coordinates and area descriptions.
Bureau of Ocean Energy Management, Regulation and Enforcement, Mapping and Boundary Branch