Low-water mark.-Although the term is defined in a well-known dictionary as “A line or mark indicating low water," there is no low-water mark left by the tide on a seacoast. There is nothing visible which is analogous to the "mark” left by high waters in many areas, by transported sand and debris and by algae and other growth on tidal rocks.

Low-water datum.—A horizontal plane for referencing depths of water on hydrographic charts. "An approximation to the plane of mean low water that has been adopted as a standard reference plane for a limited area and is retained for an indefinite period regardless of the fact that it may differ slightly from a better determination of mean low water from a subsequent series of observations." 15 The intersection of this plane with the land is what is usually meant, or should be meant, by "low tide line," "low water mark" and similar terms relating to the base line from which the territorial sea is measured.

Island is a term requiring definition when a body of "land" is submerged at high tide and awash at low tide. See the discussion below, page 547. 3. Ocean Bottom Features

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Continental Shelf.-The zone around a continent, extending from the lowtide line to a depth at which there is a marked steepening of slope to greater depths. Conventionally, its outer edge is taken at 100 fathoms (alternatively 200 meters)," but it may lie betwen 20 and 300 fathoms (it is believed to average about 72 fathoms or 132 meters).

Continental Slope.—The declivity from the outer edge of the continental shelf into deeper water. (Its base is commonly between 2,000 and 3,000 fathoms.)

Island Shelf.-The zone around an island or island group, extending from the low-tide line to a depth at which there is a marked steepening to greater depths.

Island Slope. The declivity from the outer edge of the island shelf into deeper water.

Continental Borderland.—The zone between low-tide line and continental slope that, unlike the continental shelf, is broken into basins, islands, and banks. (When the zone between the lines of permanent immersion is broken into basins, islands, and elevations, the term "Continental Borderland" is appropriate.) 4. Phrases in Common Use

A number of phrases frequently used in relation to the territorial sea should be critically examined as to their true intent and possible improvement.

"Following the sinuosities of the coast" is valid only in reference to the inner or landward limit of the territorial sea, and is appropriate in certain legal connotations. When used with regard to the seaward limit of the territorial sea the phrase is irrelevant because only the salient points on the coast usually count in actually determining the seaward limit. "Taking into consideration all points on the coast" would convey the intended meaning when applied to the seaward limit of the territorial sea. (See Fig. 1 below.)

"Drawn parallel to the general_trend of the coast" is an ambiguous phrase that is too frequently employed. It should be avoided if possible. (See Fig. 1 and explanatory text, in this Journal, Vol. 24 (July 1930), p. 546.)

Many casually phrased terms, such as "on the perpendicular of the coast," "an imaginary line parallel to the coasts," and "the line following the geographic parallels" appear in laws, decrees, and sometimes in treaties. Any terminology that is intended to specify the limits of the territorial sea or of any contiguous zones should be submitted to an expert in surveying and mapping, in hydrography, or in navigation, for assistance in making the text convey the precise meaning that is intended, so that an engineer can lay the line down on the charts, or demarcate the line by range marks on the land or by buoys or other means in the water, if that should be feasible.

II. DELIMITATION PRINCIPLES AND TECHNIQUES

The principles and techniques which are formulated and explained below relate to emerging categories of water boundary delimitation that have not hitherto claimed serious attention of students. They are designed and believed

15 U. S. Coast and Geodetic Survey, Tide and Current Glossary (Spec. Publication No. 228, 1949 ed., p. 20). See p. 23 for definitions of "Mean low water," "Mean low water springs," and "Mean lower low water."

16 This group of definitions is taken from the report of the U. S. representatives on the International Committee on Nomenclature of Ocean Bottom Features. It is therefore still subject to technical improvements by experts in the field.

17 100 fathoms is exactly 600 ft. or 182.88 meters; 200 meters is exactly 109.36 fathoms,

to be of general applicability, and are independent of the width of the belts of waters claimed, whether 3, 4, 6, or 12 miles, "contiguous zones" (also called "adjacent zones"), the "continental shelf," or even 200 miles or something else. Delimitation principles and techniques will be considered in the order listed below:

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1. Seaward limit of the territorial sea, and of any contiguous zone or zones; 2. Base lines for delimiting the territorial sea;

3. Outer limit of inland waters (a special "base line" problem);

4. Median line techniques-in gulfs, lakes, etc.;

5. Lateral boundaries through the territorial sea, from land to high seas; and 6. Lateral jurisdictional lines of contiguous zones-as far out as desired, e. g., to a median line in a gulf or lake, or to the edge of the "continental shelf." For economy of space and convenience in formulating delimitation techniques, the following abbreviations are used hereafter in the present article, whenever convenient:

T=width of the territorial sea (3 nautical miles, 4, 6, 9, 12, etc.) claimed by any coastal state, measured from the low-tide line.

C=width of the "contiguous zone" claimed (in nautical miles), always measured from the low-tide line, and therefore including the territorial sea.

1. Seaward Limit of the Territorial Sea 19 and of any Contiguous Zones The first principle in delimintation of all seaward areas of national jurisdiction is that we should begin by laying down the outer limit of the territorial sea, and similarly of the contiguous or adjacent zone or zones if there be any. This is in accord with the comprehensive proposals for the delimitation of the territorial sea submitted by the United States Delegation at The Hague in 1930.

"The American proposal was based on the assumption that, since we cannot choose our coasts but must take them as we find them, so the limit of the territorial sea, once the breadth of the belt is agreed upon, must be a

15 An additional category was originally planned: Zones of access to the high seas, by surface and air, for states apparently denied access from relatively short coasts on bays or gulfs, because the usual delimitation techniques would pinch them off from the high seas. Problems would have been considered such as those of the Gulf of Aqaba, where both Israel and Jordan have very short coasts, between those of Egypt and Saudi Arabia, and where the differences of navigability by surface ships and maneuverability of airplanes within zones of access that might be delimited by special techniques are significant. But each case is almost unique; general principles could be stated, but perhaps no techniques of wide applicability could be evolved.

19 An article by the present writer, entitled "Delimitation of the Territorial Sea: the Method of Delimitation Proposed by the Delegation of the United States at The Hague Conference for the Codification of International Law." appeared in this JOURNAL, Vol. 24 (July 1930), pp. 541-555. The full text of the American amendment of March 27, 1930, and reproductions of the five illustrations appear in the L. of N. Acts of the Conf. for the Codification of Int'l. Law * * * Vol. III, Minutes * * * Doc. C.351 (b).M.145 (b). 1930. V, pp. 197-201.

As a technical adviser to Mr. Hunter Miller, the United States delegate in the Second Committee (on Territorial Waters), the writer served as a member of the Technical SubCommittee, and worked for nearly a month with the technical men from the thirty-eight other participating countries not counting the Soviet Union, which sent only three observers. Out of the welter of divergent claims and suggestions came "the proposal of the delegation of the United States of America which was submitted at the Conference at the session of March 27, 1930, [which] represented an attempt to view all of the problems of delimitation [of the seaward and landward limits of the territorial sea] as a whole, and to set forth a body of rules both simple in application and definite in result" (Boggs, loc. cit., p. 541). The proposal was very favorably received and was discussed at length in sessions of the full Second Committee. But, as not infrequently happens in international conferences, the technical specialists were much nearer agreement than the political delegates. Vice Admiral Henry G. Surie, the very able Chairman of the Technical Sub-Committee, in acknowledging a reprint of the article referred to, concluded: "I am sure if at any moment the Codification Committee of the League of Nations will retake the problem of the Territorial Sea, your method of delimitation will be adopted as being, as you so justly said in the last line of your article, simple, impartial, and clear."

These American amendment techniques have been used at least in the following official United States studies and reports:

(a) On a series of U. S. C. & G. S. charts of the United States especially prepared for use by the U. S. Tariff Commission in an investigation of fishing problems, under Senate Resolution 314, 71st Cong., 2d Sess., adopted July 2, 1930, 72 Cong. Rec. 12376; the report of the Commission states: "The line was drawn for the purposes of this investigation in accordance with the method of delimitation proposed by the delegation of the United States at The Hague Conference for the Codification of International Law at the session of March 27, 1930. The details of this plan are given in the American Journal of International Law for July 1930." (S. Doc. 8, 72d Cong., 1st Sess., pp. 1-2.)

(b) The techniques were used, with minor adaptations, by the U. S. Bureau of the Census to determine the areas within the outer limits of the United States, and of the Individual States, in coastal waters and the Great Lakes, for the 1940 Census (16th Census of the United States, 1940, Vol. 37, p. 2).

(c) The Department of Justice has urged adoption of these techniques in cases now pending before the U. S. Supreme Court.

line which is derived directly from the coast-line, in an automatic manner except where allowance must be made for existing agreements and situations." 20

The technique for delimiting the outer limit of the territorial sea is as simple as the use of litmus paper to determine whether a solution is acid or alkali. A portion of the northern coast of Norway is used as an example in Figure 1. The technique is independent of the breadth of the territorial sea, and the Norwegian 4-mile claim is here used. If 4-mile arcs are drawn from all points on a sinuous coast and from all offshore islands, the outer or seaward limit will be the envelope of all such arcs, and will be found to constitute arcs drawn only from salient points on mainland and islands."

The general principle for delimiting the seaward limit of the territorial sea, in the language of the American amendment presented at The Hague Conference, reads as follows:

"Except as otherwise provided in this Convention, the seaward limit of the territorial waters is the envelope of all arcs of circles having a radius of three nautical miles drawn from all points on the coast (at whatever line of sea level is adopted in the charts of the coastal State), or from the seaward limit of those interior waters which are contiguous with the territorial waters." "

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To illustrate delimitation of any contiguous zone the 12-mile "envelope" (as claimed, for example, by the Soviet Union on its own coasts, though apparently not admitted on the coasts of other countries) is also shown on Figure 1. Theoretically 12-mile arcs would be described from all points of the coast, including outlying islands. Actually the "envelope" will be seen to constitute 12-mile arcs drawn only from some, but not all, of the salient points which were found to have been used in delimiting the 4-mile “envelope." The same would be true with the 3-mile envelope, or with a 6-mile zone. Of course, the wider the belt the smaller the number of salient points that determine its "envelope of arcs.” If the international community were to reach agreement on the recognition of one or more contiguous zones, for specific and limited purposes, the technique proposed above will afford precise delimitation."

With reference to the assimilation of objectionable “pockets of high sea” as proposed by the American Delegation at the Hague Conference, 1930, see this JOURNAL, Vol. 24 (1930), pp. 552-553 and Fig. 6 on p. 547. In the writer's viewpoint, the elimination of unworkable pockets of the high sea is an essential principle in the delimitation of the territorial sea.

29 This Journal, Vol. 24 (July 1930), p. 541.

21 For a graphic indication of "the navigator's method of ascertaining whether he is in territorial waters or on the high sea" see this Journal. Vol. 24 (1930), p. 546, Fig. 2; or see the same in Gilbert Charles Gidel, Le Droit International Public de la Mer, Tome III, La Mer Territorial et la Zone Contigüe, Planche I, Fig. 5.

22 This Journal, Vol. 24 (1930), p. 544.

In the compilation of the map entitled "World: National Claims in Adjacent Seas," referred to above, footnote 4, and in the accompanying table, the United States is represented as claiming a continguous zone 12 miles wide (i. e., including the 3-mile territorial sea). This may surprise some people, but the provisions of the Tariff Act of 1790 relating to customs inspection, which have been repeated in all subsequent tariff acts, are strictly analogous to the criteria employed by the writer in determining whether other countries claim a contiguous zone.

The

24 A development relating to "contiguous zones" that may be reasonable is suggested below. The high seas are generally acknowledged to be res communis. The sea bed and its subsoil somewhat beyond the 3-mile limit, or at least their exploitable natural resources, have been assumed by several nations in recent years to be res nullius over which they therefore have the right to make unilateral assertions of jurisdiction, and in some cases full sovereignty. There may be two very great resources, hitherto practically untapped, beyond the seaward limit of the territorial sea : (a) petroleum and possibly other minerals; and (b) marine life in the productive levels of the sea perhaps 200 to 1,000 feet beneath the surface. Little is known of the latter at present, but marine biologists and oceanographers are attempting systematic studies of the possible utilization of these elusive resources. seas cover nearly three-fourths of the earth's surface, and the importance of subsurface marine life as a source of proteins and vitamins and other needed materials may be great by the time a knowledge of the population structure of individual marine species is acquired, and when gear is devised to harvest the crop. The significance here is that the net revenues that will in time be available from the exploitation of minerals and marine life in the vast sea areas that come to be regarded as res communis, may eventually be very considerable, and it might be agreed upon as an independent source of income for the international agencies, especially the United Nations and the specialized agencies. Because such exploitation depends almost entirely upon the development of new techniques, it would not deprive any nation of a present source of income.

FIG. 1.-Seaward limit of the territorial sea and of any contiguous zones. On a portion of the northwest coast of Norway the technique of laying down the outer limit of the territorial sea is here illustrated. The Norwegian claim of a 4-mile limit is here used. Arcs of radius T-4 nautical miles are described from all salient points on the coast (A, B, C, D, E, etc.), including outlying islands. The "envelope of the arcs of circles of 4-mile radius drawn from all points on the coast" constitutes the outer limit of the territorial sea, and is thus the line every point of which is exactly T miles from the nearest point on the shore.

The minor "gain" in areas of exclusive jurisdiction frequently achieved by drawing a series of artificial straight lines as part of the "base line" is illustrated by the small area between the broken-line "4-mile fishing limit" (by Norwegian decree of July 12, 1935) and the envelope of 4-mile arcs.

The technique of laying down the limit of any contiguous zone is seen to be the same as for the territorial sea. For purposes of illustration a contiguous zone 12 miles wide is here assumed, constituting the arcs A", B'', E", H', etc. The wider the contiguous zone the fewer will be the number of salient points that actually determine its "envelope"; but all of these salient points will also be among those that determine the outer limit of the territorial sea.

2. Base Lines for Delimiting the Territorial Sea, etc.

Much of the difficulty in agreeing upon principles and techniques of delimitation of the territorial sea derives from the eagerness of some people to begin by drawing a series of artificial "base lines," as if nature were niggardly in providing what men require in this regard. Many officials, in their patriotic efforts to fence off maximum areas of waters which they hope will go unchallenged, begin by drawing artificial base lines along concave coasts, between islands, and across bays, gulfs, and estuaries. This office-desk approach, in geographical situations as varied as the good earth affords, yields results that defy codification or the formulation of workable principles of general applicability. Broad zones of water may appear enchanting on the maps, but their authors are eligible for disillusionment if they were to examine some of them in a launch.

But if concern with "base lines" be initially confined to the definition of the mean low-tide coastline, and the delimitation of the territorial sea otherwise begin with the outer limit of the territorial sea as suggested above, it is surprising how much more workable are the results and how many obstacles are surmounted or found to be nonexistent.

As illustrated in Figure 1, the "envelope of arcs" of T-mile radius constituting an unbroken or continuous series of arcs may actually be described from a series of salient points, including islands, and does not require a continuous “base line.” Precise identification is needed of the base lines from which delimitation is made of: (a) the marginal or territorial sea; (b) median lines in lakes and gulfs; and (c) lateral jurisdictional lines, from the termini of land boundaries out as far as may be desired-to the high seas, to a median line, or even across the continental shelf. It might be supposed that the base lines would be identical in all these cases, but it will be found that they should differ in the inclusion or the exclusion of islands (for reasons that will be explained later), as follows: (a) In delimiting the seaward limit of the territorial sea all bona fide islands must be taken into consideration;

(b) In laying down a median line in a gulf or lake, and also in laying down a lateral boundary from the coast out to the high sea, practically all islands should be, at least initially, disregarded, and therefore do not constitute part of the base line.

Base-line problems are chiefly of three types:

(a) The shoreline, essentially the tidal datum or plane on which the hydrographic charts are based;

(b) The line between inland waters and territorial sea-in bays, gulfs, etc., where it serves as an artificial coastline in delimiting the territorial sea and, conceivably in part, median lines and lateral jurisdictional lines (considered separately under later headings); and

(c) The definition of "island"-to determine which islands are to be used and which are to be ignored in delimiting the territorial sea, etc.

The three types-(a) the shoreline, (b) artificial coastlines, and (c) the definition of "island"-are here considered:

(a) Shortline base lines.-The generally accepted intent is that the territorial sea shall be delimited outwardly from the mean low-water coastline (whether the belt be 3, 4, 6, or more miles wide). The base line " differs, however, on charts of different countries, and, in fact, sometimes on charts of different scales published at different times by a single country. If precise delimitation is necessary (requiring large-scale charts), e. g., in shallow waters near the mouth of a large river such as the Yangtze or the Ganges, charts must be found on which the proper base line is represented.

Most hydrographic charts are on scales too small to permit representing both the high-tide and the low-tide coastlines. On practically all but the largest scale charts the shoreline represented is the mean high-tide line; but the soundings indicated in the sea areas are based on the low-tide datum. In other words, the practice believed best adapted to the requirements of the navigator (for safety of life and property at sea) is to represent as the land area that which always appears as land, even at high tide; but also to indicate the minimum water depth as experienced at mean low tide. The "low water datum" used by chart-producing countries varies considerably, "but is usually lower than mean low water." When the scale of the chart permits, and the range of tide is sufficiently great to justify or require it, the maximum height of water (i. e., at mean high tide) covering the narrow belt of land subject to the tide is shown in numerals that are differentiated from those in the seaward areas, by underscore or by special type."

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25 The base line proposed in the Report of Sub-Committee No. II [The "Technical SubCommittee"] at The Hague Conference, 1930, was defined as follows: "Subject to the provisions regarding bays and islands, the breadth of the territorial sea is measured from the line of low-water mark along the entire coast.

"For the purposes of this Convention, the line of low-water mark is that indicated on the charts officially used by the Coastal State, provided the latter line does not appreciably depart from the line of mean low-water spring tides."

20 A good example of a chart on which both the high-tide coastline and the low-tide line are indicated, and the zone normally covered and uncovered each tidal day (once or twice, depending on the type of tide in the area), is U. S. Hydrographic Office chart No. 3218, approaches to the Yangtze River, scale c. 1: 121,000, on which soundings are shown in feet "reduced to the approximate level of Lowest Low Water." As this is a region of relatively large differences between high and low tides, and also one of silt deposition from the Yangtze River, a coastal zone ranging up to about 5 nautical miles wide appears on the chart, showing in a special color the land between low and high tides, and tidal differences up to 18 ft. Similarly these areas that uncover at low tide are shown adjacent