711.022/3–452

The Acting Secretary of State to the Attorney General of the United States ( McGrath )

My Dear Mr. Attorney General: Reference is made to your letter dated October 30, 19511 requesting a statement from the Department of State in regard to the position of the United States as to the principles or criteria which govern the delimitation of the territorial waters of the United States. You ask in particular how such delimitation is made in the case of:

(a)
A relatively straight coast, with no special geographic features, such as indentations or bays;
(b)
A coast with small indentations not equivalent to bays;
(c)
Deep indentations such as bays, gulfs, or estuaries;
(d)
Mouths of rivers which do not form an estuary;
(e)
Islands, rocks or groups of islands lying off the coast;
(f)
Straits, particularly those situated between the mainland and offshore islands.

In the formulation of United States policy with respect to territorial waters and in the determination of the principles applicable to any problem connected therewith, such as the problem of delimiting territorial waters, the Department of State has been and is guided by generally accepted principles of international law and by the practice of other states in the matter.

(a)
In the case of a relatively straight coast, with no special geographic features such as identations or bays, the Department of State has traditionally taken the position that territorial waters should be measured from the low water mark along the coast. This position was asserted as early as 1886 (The Secretary of State, Mr. Bayard, to Mr. Manning, Secretary of the Treasury, May 28, 1886, I Moore, Digest of International Law, 720). It was maintained in treaties concluded [Page 886] by the United States. (See Article 1 of the Convention concluded with Great Britain for the Prevention of Smuggling of Intoxicating Liquors on January 23, 1924, 43 Stat. 1761.) This position was in accord with the practice of other states. (See Article 2 of the Convention between Great Britain, Belgium, Denmark, France, Germany and the Netherlands for regulating the Police of the North Sea Fisheries signed at The Hague, May 6, 1882, 73 British and Foreign State Papers, 39, 41, and Article 2 of the Convention between Germany, Denmark, Estonia, Finland, France, the British Empire, Italy, Latvia, Poland and Sweden, relating to the Non-Fortification and Neutralization of the Aaland Islands, concluded at Geneva on October 20, 1921, 9 League of Nations Treaty Series, 212, 217.) The United States maintained the same position at the Conference for the Codification of International Law held at The Hague in 1930. (See League of Nations, Bases of Discussion for the Conference for the Codification of International Law, II, Territorial Waters, C. 74 M. 39, 1929, V., 143, hereinafter referred to as Bases of Discussion.) The report of the Second Sub-Committee adopted the low water mark as the base line for the delimitation of territorial waters. (League of Nations, Acts of the Conference for the Codification of International Law, III, Territorial Waters, C. 351 (b) M. 145 (b), 1930, V., 217, hereinafter referred to as Acts of Conference.)
(b)
The Department of State has also taken the position that the low water mark along the coast should prevail as the base line for the delimitation of territorial waters in the case of a coast with small indentations not equivalent to bays: the base line follows the indentations or sinuosities of the coast, and is not drawn from headland to headland. This position was already established in 1886. (See the letter from the Secretary of State, Mr. Bayard to Mr. Manning, Secretary of the Treasury, dated May 23, 1886, supra.) The United States maintained this position at the Hague Conference of 1930. (See Amendments to Bases of Discussion proposed by the United States, Acts of Conference, 197.) The principle that all points on the coast should be taken into account in the delimitation of territorial waters was adopted in the report of the Second Sub-Committee. (Acts of Conference, 217)
(c)
The determination of the base line in the case of a coast presenting deep indentations such as bays, gulfs, or estuaries has frequently given rise to controversies. The practice of states, nevertheless, indicates substantial agreement with respect to bays, gulfs or estuaries no more than 10 miles wide: the base line of territorial waters is a straight line drawn across the opening of such indentations, or where such opening exceeds 10 miles in width at the first point therein where their width does not exceed 10 miles. (See Article 2 of the Convention between Great Britain, Belgium, Denmark, France, Germany and the Netherlands, for regulating the Police of the North Sea Fisheries, signed at the Hague, May 6, 1882, 73 Foreign and British State Papers, 39, 41; The North Atlantic Coast Fisheries Arbitration between the United States and Great Britain of September 7, 1910, U.S. Foreign Rel., 1910 at 566; and the Research in International Law of the Harvard Law School, 23 American Journal of International Law, SS, 266.)
Subject to the special case of historical bays, the United States supported the 10 mile rule at the Conference of 1930 (Acts of Conference, 197–199) and the Second Sub-Committee adopted the principle on which the United States relied (Acts of Conference, 217–218). It was understood by most delegations that, as a corollary to the adoption of this principle, a system would be evolved to assure that slight indentations would not be treated as bays (Acts of Conference, 218). The United States proposed a method to determine whether a particular indentation of the coast should be regarded as a bay to which the 10 mile rule would apply (Acts of Conference, 197–199). The Second Sub-Committee set forth the American proposal and a compromise proposal offered by the French delegation in its report, but gave no opinion regarding these systems. (Acts of Conference, 218–219.)
(d)
With respect to mouths of rivers which do not flow into estuaries, the Second Sub-Committee agreed to take for the base line a line following the general direction of the coast and drawn across the mouth of the river, whatever its width. (Acts of Conference, 220.)
(e)
With respect to the measurement of territorial waters when rocks, reefs, mudbanks, sandbanks, islands or groups of islands lie off the coast, the United States took the position at the Conference that separate bodies of land which were capable of use should be regarded as islands, irrespective of their distance from the mainland, while separate bodies of land, whether or not capable of use, but standing above the level of low tide, should be regarded as islands if they were within three nautical miles of the mainland. Each island, as defined, was to be surrounded by its own belt of territorial waters measured in the same manner as in the case of the mainland. (Acts of Conference, 200.)
The report of the Second Sub-Committee defined an island as a separate body of land, surrounded by water, which was permanently above high water mark, and approved the principle that an island, so defined, had its own belt of territorial sea. (Acts of Conference, 219.) While the Second Sub-Committee declined to define as islands natural appendages of the sea-bed which were only exposed at low tide, it agreed, nevertheless, that such appendages, provided they were situated within the territorial sea of the mainland, should be taken into account in delimiting territorial waters. (Acts of Conference, 217.)
(f)
The problem of delimiting territorial waters may arise with respect to a strait, whether it be a strait between the mainland and offshore islands or between two mainlands. The United States took the position at the Conference that if a strait connected two seas having the character of high seas, and both entrances did not exceed six nautical miles in width, all of the waters of the strait should be considered territorial waters of the coastal state. In the case of openings wider than six miles, the belt of territorial waters should be measured in the ordinary way. (Acts of Conference, 200–201.) The report of the Second Sub-Committee supported this position with the qualification that if the result of this determination of territorial waters left an area of high sea not exceeding two miles in breadth surrounded by territorial sea, this area could be assimilated to the territorial sea. (Acts of Conference, 220.)
The Second Sub-Committee specified in its observations on this subject that the waters of a strait were not to be regarded as inland waters, even if both belts of territorial waters and both shores belonged to the same state. (Acts of Conference, 220). In this, it supported the policy of the United States to oppose claims to exclusive control of such waters by the nation to which the adjacent shore belonged. (The Secretary of State, Mr. Evarts, to the American Legation, Santiago, Chile, January 18, 1879, in connection with passage through the Straits of Magellan, I Moore, Digest of International Law, 664.) With respect to a strait which is merely a channel of communication to an inland sea, however, the United States took the position, with which the Second Sub-Committee agreed, that the rules regarding bays should apply. (Acts of Conference, 201, 220.)
In connection with the principles applicable to bays and straits, it should be noted that they have no application with respect to the waters of bays, straits, or sounds, when a state can prove by historical usage that such waters have been traditionally subjected to its exclusive authority. The United States specifically reserved this type of case at the Hague Conference of 1930. (Acts of Conference, 197.)

The principles outlined above represent the position of the United States with respect to the criteria properly applicable to the determination of the base line of territorial waters and to the demarcation between territorial waters and inland waters.

Sincerely yours,

[James E. Webb]
  1. Not printed.