Admiralty law exclusively governs the issues and activities that occur at sea or in any navigable waters. Admiralty law includes violations of maritime rules and regulations, seaboard accidents and injuries, commerce and contractual relations, as well as other related activities that occur at sea. In the United States, jurisdiction over admiralty law is held at the federal court level.
The courts and Congress seek to create a uniform body of admiralty law both nationally and internationally in order to facilitate commerce. The federal courts derive their exclusive jurisdiction over this field from the Judiciary Act of 1789 and from Article III, § 2 of the U.S. Constitution. Congress regulates admiralty partially through the Commerce Clause. American admiralty law formerly applied only to American tidal waters. It now extends to any waters navigable within the United States for interstate or foreign commerce. In such waters, admiralty jurisdiction includes matters not involving interstate commerce, including recreational boating.