Outer Continental Shelf lease blocks are generated, in accordance with title 30, U.S. Code of Federal Regulations (CFR) 256.8, to define small geographic areas that identify federal land ownership and support offshore resource management.
A standard lease block is 2,304 hectares (4,800 meters X 4,800 meters), except in the Gulf of Mexico, where there are multiple standard sizes, none greater than 5,760 acres. Blocks may be smaller if they are clipped by an existing marine boundary (for instance, international boundary, federal-state boundary, or Universal Transverse Mercator (UTM) Zone boundary).
The Bureau of Ocean Energy Management (BOEM) has developed offshore administrative lines from each adjoining coastal state. The BOEM undertook this task in light of the increasing number and type of activities on the OCS related to traditional and non-traditional energy, alternative energy, and other activities. To the extent practicable, the updated National Baseline (or U.S. Supreme Court-fixed baselines, where they exist) was used to derive offshore administrative boundaries in compliance with accepted cartographic practice.