The Territorial Sea and Other Maritime Zones
(p. 255) 11 The Territorial Sea and Other Maritime Zones1
1. The Territorial Sea
(A) Introduction
Traditionally states were regarded as exercising sovereignty, subject to a right of innocent passage, over a belt of sea adjacent to their coastlines and bounded by the high seas. The breadth of this ‘territorial sea’2 was never definitively settled despite codification attempts in 1930, 1958, and 1960; claims varied between three and six nautical miles (nm) and even more.3 It came to be understood that the territorial sea was founded on a baseline, related to the low-water mark, and enclosing internal waters (rivers, bays, gulfs, harbours, etc) lying on its landward side. Both the 1958 Geneva Convention on the Territorial Sea and Contiguous Zone (GCTS)4and the UN Convention on the Law of the Sea (UNCLOS)5 assume that every coastal state has a territorial sea.6
References(p. 256) Following early debate,7 it came to be settled that states have sovereignty over the territorial sea. GCTS Article 2 and UNCLOS Article 3 both state that sovereignty is exercised subject to the provisions of the respective conventions and other rules of international law. This was intended to highlight that the limitations upon sovereignty in this area set out in the Convention are non-exhaustive. The sovereignty of the coastal state extends to the seabed and subsoil of the territorial sea and the airspace above it.8
An understanding of the modern law depends on an understanding of its history. In the eighteenth century extravagant claims to sovereignty over the seas came to be seen as obsolete or nearly so. In 1702, the Dutch jurist Bynkershoek propounded the doctrine that the power of the territorial sovereign extended to vessels within cannon range of shore.9 At first this doctrine seemed commensurate with the control of the actual guns of ports and fortresses over adjacent waters: it was not a maritime belt of uniform breadth.10 However, in the latter half of the eighteenth century, several states laid down limits for belts for purposes of customs or fishery control in legislation and treaties, and Danish practice—after 1745 based on a four-mile belt11—had some impact on European thinking.12
In the later eighteenth century, two developments occurred. Writers and governments conceived of a hypothetical cannon-shot rule, a belt over which cannons could range if they were placed along the whole seaboard. Further, as ‘cannon-shot’ was a somewhat imprecise criterion, suggestions for a convenient substitute appeared. In 1782, the Italian writer Galiani proposed three nautical miles, or one marine league.13The diplomatic birth of the three-mile limit appears to have been the US Note to Britain and France of 8 November 1793, in which the limit was employed for purposes of neutrality.14 During and after the Napoleonic wars, British and American prize courts translated the cannon-shot rule into the three-mile rule.15
A significant legal development was the shift from claims to jurisdiction for particular purposes to the extension of sovereignty over a maritime belt. Some claims, such as those of Denmark and Sweden, though commencing as pronouncements forReferences(p. 257) neutrality purposes, quickly developed into assertions of sovereignty,16 especially when associated with exclusive fishery limits. In other cases it remained unclear whether a claim was only to certain types of jurisdiction or a general limit of sovereignty.17
Such claims to jurisdiction have tended to harden into claims to sovereignty, and indeed a few states still claim a territorial sea or other zone of sovereignty beyond 12nm, the limit now laid down by UNCLOS Article 3. This process was, however, arrested to some extent by recognition of a legal distinction between the territorial sea as an extension of sovereignty and special jurisdictional zones.18 A variety were claimed during the twentieth century, and four were eventually accepted, namely the contiguous zone, the continental shelf and the exclusive economic zone (EEZ), and (in certain cases) archipelagic seas. These are now regulated by UNCLOS, with non-parties showing little disposition to challenge its provisions. UNCLOS characterizes the coastal state’s rights over the continental shelf and the EEZ as ‘sovereign rights’, but they co-exist with high seas rights applicable to other matters, notably maritime transit, the laying of submarine cables, etc (see chapter 13).
(B) The Baseline for Measurement of the Territorial Sea
The baseline from which the breadth of the territorial sea is measured is normally the coastal low-water line.19There is no standard by which states determine this line, although UNCLOS Article 5 defines the line ‘as marked on large scale charts officially recognised by coastal States’.20
References(p. 258) At one time it was arguable that the baseline was for all purposes the low-water mark. But in the signal case Anglo–Norwegian Fisheries the Court decided otherwise.21
The Norwegian limit of four nautical miles for territorial waters had been established by royal decree in 1812 and was not at issue in the case. However, later decrees of 1869, 1881, and 1889 continued the measure of 1812 in terms of a system of straight lines drawn from certain outermost points of the skjaergaard or rampart of rocks and islands which fringes much of the Norwegian coast. By a decree of 12 July 1935, Norway applied the system in a more detailed way, and the validity of the new limits was challenged by the UK. After a series of incidents, the UK took the case to the Court, seeking damages for interference with British fishing vessels outside the permissible limits.22 The Court held that the system of straight baselines following the general direction of the coast had been consistently applied by Norway and was unopposed by other states. The UK had not explicitly protested the position of baselines until 1933.23 Thus the decree of 1935 could have been upheld on the basis of acquiescence; indeed, Judge Hackworth would have upheld Norway’s historic title to the areas in question.24
But the Court went further, holding that the Norwegian system of baselines was lawful in principle.25 It stressed the broken and indented character of the Norwegian coastline:26 to draw the baseline along the outer limit of the skjaergaard was a solution ‘dictated by geographical realities’.27 By contrast, a line which was an exact image of the coastline (the tracé parallèle), assumed to be the normal method of applying the low-water mark rule,28 did not apply to a coast where the baseline could only be determined by means of a geometric construction.29
[T]he practice of States does not justify the formulation of any general rule of law…[A]part from any question of limiting the lines to ten miles, it may be that several lines can be envisaged. In such cases the coastal State would seem to be in the best position to appraise the localReferences(p. 259) conditions dictating the selection…[A]ll that the Court can see [in the Norwegian system] is the application of general international law to a specific case.30
The Court went on to elaborate criteria for determining the validity of straight baselines. First, because of the dependence of the territorial sea upon the land, ‘the drawing of baselines must not depart to any appreciable extent from the general direction of the coast’.31 Secondly, a close geographical relationship between sea areas and land formations is a ‘fundamental consideration’ in deciding ‘whether certain sea areas lying within [the baselines] are sufficiently closely linked to the land domain to be subject to the regime of internal waters’.32Thirdly, it is relevant that there exist ‘certain economic interests peculiar to a region, the reality and importance of which are evidenced by long usage’.33
Even if one regards Anglo-Norwegian Fisheries as an instance of judicial legislation, its significance for the development of the law cannot be underestimated. The Court’s pronouncements on the straight lines method were intended to have general application to coasts of that type. They have been codified in GCTS Article 4 and UNCLOS Article 7, which confirm the place of Anglo-Norwegian Fisheries in the modern law of the sea. A good number of states employ straight baselines, although not always in conformity with the rules.34
UNCLOS Article 14 provides that ‘[t]he coastal State may determine baselines in turn by any of the methods provided for…to suit different conditions.’ Thus straight baselines may be used in conjunction with closing lines across river mouths35 and bays.36 Furthermore, under UNCLOS Article 7(2) straight baseline systems may apparently be maintained despite changes in coastal morphology.
(C) Breadth of the Territorial Sea37
In the seventeenth century several forms of limit were known, including the range of vision on a fair day and the range of cannons on shore. By the last quarter of the eighteenth century, the cannon-shot rule obtained in western and southern Europe. It was not dominant, however, and other claims rested simply on a belt with a stated breadth.38 In 1793, the cannon-shot rule was first given a standard value of one marine leagueReferences(p. 260) or three nautical miles in diplomatic practice.39 By 1862,40 and probably earlier, the cannon-shot rule and the three-mile limit were generally regarded as synonymous.41
The three-mile limit gained currency during the nineteenth century. However, practice was not uniform,42 and France, Belgium, Portugal, Germany, and Russia did not differentiate clearly in their practice between territorial sea and jurisdictional zones. Many states with a three-mile limit claimed contiguous zones extending beyond three nautical miles.
Thus some jurists doubted whether the three-mile limit had been unequivocally settled.43 The results of the Hague Codification Conference of 1930 provide a significant balance sheet. Although a majority of states favoured a three-mile limit, some also claimed contiguous zones. In its report to the Conference the second committee explained that, due to differences of opinion, it preferred not to express any conclu-sion.44 Likewise the ILC indicated that a majority of members did not regard the three-mile rule as positive law.45 It proved impossible to agree on a limit at UNCLOS I (1958) and II (1960). But as part of the trade-off which occurred at UNCLOS III, agreement was reached. UNCLOS Article 3 provides that ‘every state has the right to establish the breadth of its territorial sea up to a limit not exceeding 12 nautical miles’.
Until 1987 and 1988 respectively, the US and the UK supported the three-mile limit and protested wider claims. British adherence to the three-mile limit was reinforced by the legislative embodiment of the limit, commencing with the Territorial Waters Jurisdiction Act 1878. Now, however, most states have a 12nm limit,46 including non-parties to UNCLOS such as the US.47 Claims apparently in excess of 12nm call for careful assessment. Certain of these are fishing conservation zones, wrongly characterized.48
References(p. 261) (D) Bays49
In certain circumstances, bays may be enclosed by a line which leaves internal waters on its landward side and provides a baseline for delimiting the territorial sea.
(i) Bays the coasts of which belong to a single state
The drawing of a closing line is possible only where the coast of the bay belongs to a single state. GCTS Article 7(2) and UNCLOS Article 10(2) provide a geometrical, semicircle test for bays.50 This is a necessary but not sufficient condition for the existence of a bay: there must be ‘a well-marked indentation with identifiable headlands’.51 Gulfs, fjords, and straits, or parts thereof, are not excluded from the legal concept of a bay. On the other hand the provisions concerning bays are not intended to introduce the system of straight lines to coasts whose configuration does not justify this.
It was asserted formerly that the closing line was limited to 10nm. Practice was, however, not uniform,52 and in Anglo-Norwegian Fisheries the International Court concluded that ‘the ten-mile rule has not acquired the authority of a general rule of international law’.53 GCTS Article 7(4) and UNCLOS Article 10(4) prescribe 24nm.
Coastal states may derive title to bays as a consequence of the Anglo-Norwegian Fisheries system of straight lines. A considerable number of claims related to ‘bays’ are based on historic title, often on questionable or equivocal evidence.54
(ii) Bays bounded by the territory of two or more states
Where the coasts of two States are opposite or adjacent to each other, neither of the two States is entitled, failing agreement between them to the contrary, to extend its territorialReferences(p. 262) sea beyond the median line every point of which is equidistant from the nearest points on the baselines from which the breadth of the territorial seas of each of the two States is measured.
The above provision does not apply, however, where it is necessary by reason of historic title or other special circumstances to delimit the territorial seas of the two States in a way which is at variance therewith.
The reference to ‘other special circumstances’ is vague, but seems to cater for geographical peculiarities and the elimination of practical problems.55
(E) Islands, Rocks, and Low-Tide Elevations56
(i) Definition of ‘island’
Whatever its size or population, a formation is legally an island if two conditions are satisfied: (1) the formation must be ‘a naturally formed area of land’; (2) it must always be above sea level. Permanently submerged banks and reefs generally do not produce a territorial sea, and formations visible only at low tide (low-tide elevations) will only do so in limited circumstances. Islands are ordinarily entitled to a territorial sea, contiguous zone, EEZ, and continental shelf.57
However, UNCLOS Article 121(3) provides that ‘[r]ocks which cannot sustain human habitation or economic life of their own shall have no exclusive economic zone or continental shelf ’. This provision reflects the concern that minor features permanently above sea level but otherwise insignificant should not generate extended maritime zones up to or beyond 200nm. It is unlikely that the term ‘rocks’ further restricts the application of Article 121(3) to features meeting unspecified geological criteria. A UN study on baselines published in 1989 suggests as a definition, ‘[a] solid mass of limited extent’.58 Yet proposals to limit those islands capable of supporting an EEZ by reference to size were not accepted.59 The term ‘rocks’ might be considered to refer to islands meeting conditions (1) and (2) which cannot sustain habitation or economic life of their own.
But the qualifying phrase is unclear. Is past, present, or future sustenance of human habitation or economic life sufficient? The conjunction ‘or’ may suggest that an island may generate an EEZ provided it is capable of sustaining independently either human habitation or economic life; or it may operate cumulatively. The concept of ‘economic life of their own’ is also vague:60 many small island populations are dependent onReferences(p. 263) remittances and metropolitan aid but presumably qualify as having an ‘economic life of their own’. It is possible that sovereign rights to exploit living and non-living marine resources in the territorial sea could fulfil the requirement of ‘economic life’. By contrast fisheries or sea-bed minerals beyond 12nm could not do so: otherwise every rock would be capable of sustaining economic life of its own and the provision would be entirely circular. State practice is equivocal. While the UK’s renunciation of any claim to an EEZ or continental shelf off Rockall upon acceding to UNCLOS is oft en cited in this context,61 other states continue to claim extended maritime zones for similar features.62
Whatever interpretative difficulties may attach to Article 121(3), it is part of the negotiated text and must be given effect. Moreover the only explicit definition of ‘island’ in the 1958 Conventions is in the GCTS, and it is not disputed that islands and rocks of any size are entitled to a territorial sea. What is disputed is whether they are entitled to maritime zones beyond 12nm, but the conventions do not contemplate the EEZ, and the Geneva Convention on the Continental Shelf (GCCS) is equivocal.63
(ii) Low-tide elevations64
In two cases low-tide elevations (by definition not islands) affect the limit of the territorial sea. GCTS Article 4(3) and UNCLOS Article 7(4) provide that straight baselines shall not be drawn to or from low-tide elevations unless lighthouses or similar installations which are permanently above sea level have been built on them.65 Secondly, and independently, the low-water line on an elevation situated at a distance not exceeding the breadth of the territorial sea from the mainland or an island may serve as the baseline.66 Low-tide elevations outside the territorial sea have no territorial sea of their own.
References(p. 264) (iii) Groups of islands: archipelagos67
The ILC failed to produce a draft article on archipelagos for inclusion in GCTS, although in its commentary on Article 10 it noted that the straight baselines system might be applicable.68 This provides no solution to the problem of extensive island systems unconnected with a mainland. Indonesia and the Philippines69 have for some time employed straight baselines to enclose such island systems, and it may be that a polygonal system is the only feasible one. It is arguable that this is only a further application, to special facts, of principles of unity and interdependence inherent in Anglo-Norwegian Fisheries. The difficulty is to allow for such cases without giving a general prescription which, being unrelated to any clear concept of mainland, will permit abuse.
At UNCLOS III the archipelagic states as a group70 successfully advanced the cause of straight archipelagic baselines. UNCLOS includes a Part concerning archipelagic states (Articles 46 to 54). These are defined as ‘a state constituted wholly by one or more archipelagos and may include other islands’. This definition unaccountably excludes archipelagic baselines for those states, such as Ecuador and Canada, which also consist of continental coasts as well as one or more archipelagos.
Archipelagic straight baselines may be employed subject to conditions: for example, that these baselines ‘shall not depart to any appreciable extent from the general configuration of the archipelago’. The archipelagic state has sovereignty over the waters enclosed by the baselines subject to limitations created by the provisions of this Part of the convention. These limitations consist of the right of innocent passage for ships of all states, and, unless the archipelagic state designates sea lanes and air routes, the right of archipelagic sea lanes passage ‘through the routes normally used for international navigation’.71
(F) Legal Regime of the Territorial Sea
The coastal state has all the practical rights and duties inherent in sovereignty, whereas foreign vessels have privileges, associated particularly with the right of innocent passage, which have no general counterparts in respect of the land domain. The coastalReferences(p. 265) state may reserve fisheries for national use. It may also exclude foreign vessels from navigation and trade along the coast (cabotage). Obviously, there are general police powers in matters of security, customs, fiscal regulation, and sanitary and health controls.
Foreign ships have a right of innocent passage through the territorial sea in customary law.72 GCTS Article 14 and UNCLOS Article 17 codify this right (see further chapter 13).
2. The Contiguous Zone
The power of the coastal state may be manifested in other ways. The territorial sea is, however, the form which involves a concentration of ‘sovereign’ legal rights. The general interest in maintaining the freedom of the seas outside the territorial sea has been reconciled with the tendencies of coastal states to extend their power seaward by the development of generally-recognized specialized extensions of jurisdiction and associated rights. The contiguous zone was the first to emerge.
(A) The Concept of the Contiguous zone73
There is general recognition that contiguous zones give jurisdiction beyond the territorial sea for special purposes. In 1958, the sole article on the contiguous zone was GCTS Article 24, which referred to control by the coastal state ‘in a zone of the high seas contiguous to its territorial sea’. UNCLOS Article 33 describes it simply as a zone contiguous to the territorial sea of the coastal state. Under UNCLOS Article 55 the contiguous zone, if claimed, will be superimposed upon the EEZ. In the absence of a claimed EEZ, the areas concerned form part of the high seas (see Article 86). It follows that the rights of the coastal state in such a zone do not constitute sovereignty,74 and other states have the rights exercisable over the high seas save as qualified by these jurisdictional zones.
Only recently has a consistent doctrine of contiguous zones appeared.75 UNCLOS Article 33 provides for the creation of contiguous zones for the same purposes and on the same basis as GCTS Article 24, except that (a) the contiguous zone is no longerReferences(p. 266) considered ‘a zone of the high seas’; and (b) the maximum limit is expressed to be 24nm from the territorial sea baselines. Most coastal states claim a contiguous zone within and up to this maximum limit;76these, when limited to the purposes specified in Article 33, are uncontroversial.
(B) Functional Jurisdiction in the Contiguous Zone
did not recognize special security rights in the contiguous zone. It considered that the extreme vagueness of the term ‘security’ would open the way for abuses and that the granting of such rights was not necessary. The enforcement of customs and sanitary regulations will be sufficient in most cases to safeguard the security of the State. In so far as measures of self-defence against an imminent and direct threat to the security of the State are concerned, the Commission refers to the general principles of international law and the Charter of the United Nations.79
It may be added that recognition of such rights would go far toward equating rights over the contiguous zone and the territorial sea.
(i) Customs
The exercise of this jurisdiction is frequent and no doubt rests on customary international law. UNCLOS Article 33 refers compendiously to ‘customs and fiscal’ regulations in the contiguous zone; other sources refer to ‘revenue laws’. Modern vessels would find smuggling quite straightforward if a narrow enforcement area were employed, and customs zones of 6 and 12nm were common. The US exercised customs jurisdiction over inward-bound foreign vessels within a four-league zone from 1790. The UK had similar ‘hovering acts’ operating against foreign vessels from 1736 until (p. 267) 1876.80 Claims for the enforcement of national legislation in areas of the high seas are limited by reasonableness, and regulations designed for revenue enforcement cannot be employed in such a way as to accomplish another purpose, for example the exclusion of foreign vessels.81 Treaty regimes may be created for the mutual recognition of zones and enforcement procedures, reducing the likelihood of incidents.82
(ii) Immigration
In practice customs and fiscal regulations might be applied to deal with immigration, and this jurisdiction shares the same policy basis as that relating to customs. Immigration zones were reconciled partially by inclusion in the GCTS and UNCLOS.83 The limitation to immigration may be significant, although in its 1955 report the ILC indicated that the term was intended to include emigration.84
(iii) Sanitary purposes
Although the number of States which claim rights over the contiguous zone for the purpose of applying sanitary regulations is fairly small, the Commission considers that, in view of the connection between customs and sanitary regulations, such rights should also be recognized for sanitary regulations.85
Doctrine supports this type of claim.86
Sanitary purposes might cover measures to prevent pollution, particularly by oil, but the position is unclear. Jurisdiction to police pollution has been advanced by the extension of the territorial sea and the appearance of the EEZ, wherein the coastal state has the right of conserving and managing natural resources.87 UNCLOS Part XII also sets out a general obligation to protect and preserve the marine environment.88 States are further required to take ‘all measures consistent with [the] Convention that are necessary to prevent, reduce and control pollution of the marine environment from any source’ and to ‘take all measures necessary to ensure that activities under their jurisdiction or control are so conducted as not to cause damage by pollution to other States and their environment, and that pollution arising from incidents or activities under their jurisdiction or control does not spread beyond the areas whereReferences(p. 268) they exercise sovereign rights’.89 The coastal state may adopt ‘laws and regulations for the prevention, reduction and control of pollution from vessels conforming to and giving effect to generally accepted international rules and standards’ in their EEZs.90 UNCLOS Article 220 sets out coastal state rights of enforcement in respect of vessels within its territorial sea and EEZ.
(C) Issues of Enforcement
Under general international law the coastal state may take steps necessary to enforce compliance with its laws in the prescribed zone. The power is one of police and control, and transgressors cannot be visited with consequences amounting to reprisal or summary punishment. Forcible self-help may not be resorted to as readily as in the case of trespass over a terrestrial frontier.
Thus the conventional law may be more restrictive from the perspective of a coastal state than customary law.91 Both GCTS Article 24(1) and UNCLOS Article 33 provide for the exercise of control necessary to prevent and punish infringement of customs, fiscal, immigration or sanitary laws or regulations within its territory or territorial waters. Fitzmaurice promoted this text prominently in the ILC. In his view:92
It…is control, not jurisdiction, that is exercised…[T]aken as a whole, the power is essentially supervisory and preventative. The basic object is anticipatory. No offence against the laws of the coastal State is actually being committed at the time. The intention is to avoid such an offence being committed subsequently, when, by entering the territorial sea, the vessel comes within the jurisdiction of the coastal State; or else to punish such an offence already committed when the vessel was within such jurisdiction…Whatever the eventual designs of the [incoming] vessel, she cannot ex hypothesi at this stage have committed an offence ‘within [the coastal State’s] territory or territorial sea’…As regards ordering, or conducting, the vessel into port under escort, the case is less clear. Though formally distinct from arrest, enforced direction into port is, in the circumstances, almost tantamount to it, and should therefore in principle be excluded: any necessary inquiries, investigation, examination, search, etc., should take place at sea while the ship is still in the contiguous zone.…In case this may seem to be unduly restrictive, it must be observed that only by insistence on such limitations is it possible to prevent coastal States from treating the contiguous zone as virtually equivalent to territorial sea.
This interpretation, whilst open, is not inevitable, and the travaux préparatoires indicate that most delegations at UNCLOS I did not intend to restrict rights by distinguishing between ‘control’ and ‘jurisdiction’.93 The language of GCTS Article 24 was retained in UNCLOS Article 33: again the record of negotiations does not indicate an intention to limit coastal state powers in the contiguous zone by using the termReferences(p. 269) ‘control’.94 The decision to retain the contiguous zone, however, seems to have been based upon the observation that coastal state jurisdiction in the EEZ related primarily to natural resources and did not cover the functions specified for the exercise of control in the contiguous zone. Although enforcement jurisdiction in the contiguous zone relates to the threatened or actual infringement of laws and regulations within the territory or territorial waters and does not extend jurisdiction to the contiguous zone, a small number of states argue that this limitation was not supported by the majority at UNCLOS I or by state practice.95 Nevertheless, a Polish amendment removing the reference to infringement within the territory or the territorial sea (and adding security to the list of recognized purposes for the exercise of control) failed in plenary.
3. The Continental Shelf
Submarine areas may be classified as follows: (a) the seabed of the internal waters and territorial seas of coastal states, which are under territorial sovereignty; (b) the seabed and subsoil of the EEZ, which is part of that zone; (c) the continental shelf area, which overlaps with the EEZ within 200nm but may extend further; and (d) the seabed and ocean floor beyond the outer limits of the continental shelf and EEZ, which come within the legal regime of the high seas.
UNCLOS Article 56 purports to solve the problem of overlapping regimes by providing that rights with respect to the seabed and subsoil in the EEZ shall be exercised in accordance with Part VI, that is, the continental shelf regime. But this does not solve the problem entirely, since an area may be within 200nm of state A (and thus part of its EEZ) but beyond 200nm from state B yet claimed by it as outer continental shelf.96 The legal regime of the international seabed ‘Area’ and the International Seabed Authority are discussed in chapter 13.