United States v. Maine, 469 U.S. 504 (1985)
U.S. Supreme CourtUnited States v. Maine, 469 U.S. 504 (1985)
United States v. Maine
(Rhode Island and New York Boundary Case)
No. 35, Orig.
Argued November 26, 1984
Decided February 19, 1985
469 U.S. 504
The United States brought this action against the 13 States that border the Atlantic Ocean to determine whether the United States had exclusive rights to the seabed and subsoil underlying the ocean beyond three geographical miles from each State's coastline. In due course, this Court concluded that the States held interests in the seabeds only to a distance of three geographical miles from their respective coastlines, but did not fix the precise coastline of any of the States. After the United States filed a motion for supplementary proceedings to determine the exact coastline of Rhode Island, a Special Master was appointed, and he subsequently permitted New York to participate in those proceedings. The purpose of these supplemental proceedings is to determine the legal coastline of the United States in the area of Block Island Sound and the eastern portion of Long Island Sound. This determination turns on whether the Sounds constitute, in whole or in part, a juridical bay under Article 7(6) of the Convention on the Territorial Sea and the Contiguous Zone, since to the extent the Sounds constitute a juridical bay, the waters of that bay are then internal waters subject to the adjacent States' jurisdiction, and the line that closes the bay is coastline for the purpose of fixing the seaward boundaries of the States. The Special Master filed a Report in which he concluded (a) that the Sounds in part constitute a juridical bay under Article 7(6), 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 on the Rhode Island shore, the waters of the bay west of the closing line being internal state waters, and the waters of Block Island Sound east of that line being territorial waters and high seas. The United States, Rhode Island, and New York each filed exceptions to the Report.
Held: The exceptions are overruled, and the Special Master's Report is confirmed. Pp. 469 U. S. 512-527.
(a) As a general, rule islands may not normally be considered extensions of the mainland for purposes of creating headlands of juridical bays, but may be so considered if they
"are so integrally related to the mainland that they are realistically parts of the 'coast' within the meaning of the Convention."
Long Island presents the exceptional case of an island that should be treated as an extension of the mainland. Pp. 469 U. S. 512-520.
(b) Block Island is too far seaward of the bay to affect the bay's closing line. The bay therefore does not have multiple mouths, but closes at the line drawn from Montauk Point, Long Island, to Watch Hill Point, Rhode Island. Pp. 469 U. S. 520-526.
Exceptions to Special Master's Report overruled, and Report confirmed.
BLACKMUN, J., delivered the opinion for a unanimous Court.