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18 U.S. Code § 26 - Definition of seaport

As used in this title, the term “seaport” means all piers, wharves, docks, and similar structures, adjacent to any waters subject to the jurisdiction of the United States, to which a vessel may be secured, including areas of land, water, or land and water under and in immediate proximity to such structures, buildings on or contiguous to such structures, and the equipment and materials on such structures or in such buildings.