OCS Block Polygons - 2nd Division

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.外大陆架（Outer Continental Shelf, OCS）区块是美国海洋能源管理局（Bureau of Ocean Energy Management, BOEM）用于界定租赁及行政管理用途下官方海域规划图（Official Protraction Diagram, OPD）内小型地理区域的离岸边界坐标的法定定义。此类多边形已依据《淹没土地法》边界与大陆架边界完成裁切。OCS区块关联至单幅官方海域规划图（OPD），且不具备唯一编号。区块的唯一标识为规划编号与区块编号（例如NK18-02、区块6822）。完整OCS区块的尺寸为4800×4800米。沿联邦/州级OCS边界及通用横轴墨卡托（Universal Transverse Mercator, UTM）分带边界分布有经裁切的小型等分区块。仅官方或法定用途需采用OPD或补充官方区块图（Supplemental Official Block Diagrams, SOBDs）的最新印刷版或PDF版本。此类数据最初采用适配的NAD83 UTM或NAD27 UTM/SPCS投影坐标系创建，后为适配BOEM企业地理信息系统的管理需求，被重投影至地理坐标系统WGS84（GCS WGS84, EPSG 4326）。但本数据集的此项服务采用WGS84 Web墨卡托辅助球体投影（EPSG 3857）发布。由于地理信息系统的投影与拓扑功能可能变更或泛化坐标，此类数据并非精确边界的法定备案文件。此类数据仅可用于制图用途，不得用于面积计算。