United States v. Maine, 469 U.S. 504 (1985), also known as the Rhode Island and New York Boundary Case, was a decision by the U.S. Supreme Court, which held (a) that Long Island Sound and Block Island Sound in part constitute a juridical bay under Article 7(6) of the Convention on the Territorial Sea and the Contiguous Zone, Long Island being an extension of the mainland and the southern headland of the bay, and (b) that the bay closed at the line drawn from Montauk Point at the eastern tip of Long Island to Watch Hill Point in Westerly, Rhode Island, (c) the waters of the bay west of the closing line being internal state, and (d) the waters of Block Island Sound east of that line being territorial waters and high seas.