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Oppenheim's International Law - Volume 1 Peace, 9th Edition edited by Jennings, Robert; Watts KCMG QC, Arthur (19th June 2008)

Part 2 The objects of international law, Ch.6 The high seas, The Freedom of the High Seas

Sir Robert Jennings qc, Sir Arthur Watts kcmg qc

From: Oppenheim's International Law: Volume 1 Peace (9th Edition)

Edited By: Robert Jennings, Arthur Watts KCMG QC

From: Oxford Public International Law (http://opil.ouplaw.com). (c) Oxford University Press, 2015. All Rights Reserved. Subscriber: null; date: 19 April 2019

High seas — Warfare, sea — Ships / vessels — Sovereignty

The Freedom of the High Seas

McDougal and Burke, The Public Order of the Oceans (1962) Verzijl, International Law in Historical Perspective (vol iv, 1971) Luther and Mann, Staat u Recht, 23 (1974), pp 419–28 Lapidoth, Israel Law Rev, 10 (1975), pp 456–502 Münch, Germ YBIL, 19 (1976), pp 128–42 Gidel, ‘Explosions nucléaires expérimentales et liberté de la haute mer’ in Grundprobleme des internationalen Rechts, Festschrift für Jean Spiropoulos, Bonn (1957), pp 173–205 Conforti, Ital YBIL, 6 (1985), pp 3–15 Oda, AJ, 77 (1983), pp 739–55 Allot, ibid, pp 1–30 Anand, Int Stud, 12 (1973), pp 416–29 Bardonnet and Virally, Le Nouveau droit international de la mer (1983) Riphagen, ibid, pp 141–76 Brown, San Diego Law Rev, 20 (1983), pp 521–60 O’Connell, The International Law of the Sea (ed Shearer, vol 2, 1984) Dupuy and Vignes (eds), Traité du nouveau droit de la mer (1985), pp 337–74.

§ 284  Meaning of the freedom of the high seas

The principle of freedom of the high seas means that the high seas being common to all states, no state may purport to subject any part of them to its territorial sovereignty.1

(p. 727) Since, therefore, the open sea is not the territory of any state, no state has as a rule a right to exercise its legislation, administration, jurisdiction, or police over parts of the high seas. Since, further, the high seas can never be under the sovereignty of any state, no state has a right to acquire parts of the high seas through occupation, for, as far as the acquisition of territory is concerned, the high seas are what Roman law calls res extra commercium.2 But although the open sea is not the territory of any state, it is nevertheless an object of the law of nations. The mere fact that there is a rule exempting the open sea from the sovereignty of any state whatever shows this. But there are other reasons. For if the law of nations were to content itself with the rule which excludes the open sea from possible state property, the consequence would be a condition of lawlessness and anarchy on the open sea. To obviate such lawlessness, customary international law contains some rules which guarantee a certain legal order on the open sea, in spite of the fact that it is not the territory of any state; and important international conventions have been concluded with the same object.

Apart from the rules contained in the conventions regarding salvage, assistance, collisions and safety of life at sea, which are discussed below, this legal order is created through the cooperation of the law of nations and the municipal laws of such states as possess a maritime flag. The following rules of the law of nations are universally recognised, namely: first, that every state which has a maritime flag must lay down rules according to which vessels can claim to sail under its flag, and must furnish such vessels with some official voucher authorising them to make use of its flag; secondly, that every state has a right to punish all such foreign vessels as sail under its flag without being authorised to do so; thirdly, that all vessels with their persons and goods are, whilst on the open sea, considered under the sway of the flag state; fourthly, that every state has a right to punish piracy on the open sea even if committed by foreigners, and that, with a view to the extinction of piracy, warships of all nations can require all suspect vessels to show their flag.

The principle of the freedom of the high seas excludes the establishment of sovereignty on the high seas precisely because its main purpose is to ensure that all states, whether coastal or not, enjoy, subject to law, the so-called freedoms of the high seas. This is now authoritatively stated in Article 87 of the Convention on the Law of the Sea 1982:3

(p. 728) 1. The high seas are open to all States, whether coastal or land-locked. Freedom of the high seas is exercised under the conditions laid down by this Convention and by other rules of international law. It comprises, inter alia, both for coastal and land-locked States:

(a)  freedom of navigation;

(b)  freedom of overflight;

(c)  freedom to lay submarine cables and pipelines, subject to Part VI;[4]

(d)  freedom to construct artificial islands and other installations permitted under international law, subject to Part VI;[4]

(e)  freedom of fishing, subject to the conditions laid down in Section 2;

(f)  freedom of scientific research, subject to Parts VI and XIII.[5]

2. These freedoms shall be exercised by all States with due regard for the interest of other States in their exercise of the freedom of the high seas, and also with due regard for the rights under this convention with respect to activities in the Area.[6]

§ 285  Navigation and other freedoms on the high seas

Of the six freedoms thus expressly stated, the right of fishing will be dealt with below.1 The others, apart from (f) freedom of scientific research, are all aspects of the essential role played by the high seas in providing a means of transport and communication open to all states. Thus the freedom of the open sea involves freedom of navigation for vessels of all nations, whether warships, other public vessels, or merchantmen; and absence of compulsory maritime ceremonials. No rights of salute exist between vessels meeting on the open sea. All maritime ceremonials on the open sea are a matter either of courtesy and usage, or of special conventions and municipal laws of those states under whose flags the vessels sail. No state has a right to require a salute from foreign merchantmen for its warships.2

(p. 729) The freedom of the high seas involves likewise freedom of innocent passage through the territorial sea for merchantmen of all nations, and also for warships of all nations in so far as the part of the territorial sea concerned forms a part of the highways for international traffic.

All the freedoms, whether those expressly stated in the Convention or not, are enjoyed subject to the qualification that they ‘shall be exercised by all States with due regard for the interests of other States in their exercise of the freedom of the high seas …’3 This means that in the exercise of any of the freedoms, reasonable regard must be had to the enjoyment by other states not only of that particular freedom, but of others of the freedoms; and indeed it would now seem of some other legitimate uses of a locality which might be not a freedom enjoyed by all, but an exclusive right such as the exploitation of the resources of the exclusive economic zone and the continental shelf.4 The exercise of the freedoms is also subject to specific rules concerning the user of the high seas, whether referred to in the Convention on the Law of the Sea or in other conventions, such as those concerning the safety of life at sea,5 or those concerning pollution,6 or those concerning conservation of resources.7

The list of freedoms contained in Article 87 of the Convention on the Law of the Sea, as the wording clearly indicates, is not restrictive.8 Not only are there freedoms other than those specified, but they must change from time to time, for example with the development of new technologies.9 Likewise the relative weighting of freedoms may change with circumstances and with time.

The freedoms of the high seas are enjoyed by all states. Article 3 of the Geneva Convention on the High Seas provides that, in order that land-locked states might enjoy those freedoms, they ‘should have access to the sea’, and envisages arrangements made with coastal states ‘by common agreement’. The 1982 Convention, in Part X, provides a framework of principles and rules for the purpose (p. 730) of ensuring rights of access and transit to and from the sea for land-locked states in order that they may exercise the freedoms.10

Since the freedoms in principle constitute an open and changing category, there is room for differences of opinion about marginal alleged freedoms. Naval manoeuvres, which may amount to temporary occupation of considerable areas of high seas, have been accepted in practice as coming within the category of the exercise of the freedoms. But there is obviously a question of degree to be considered; and when France in 1974 closed vast areas of the Pacific for the testing of nuclear weapons, Australia and New Zealand took the matter to the International Court of Justice. As the French Government eventually announced the termination of the testing, the Court’s Judgment does not pass upon the merits of the fundamental questions raised by the case.11

§ 286  Discrepancies between the 1958 and 1982 Conventions

There are significant discrepancies between the 1958 Geneva Convention on the High Seas and the Convention of 1982. The Geneva Convention, which is stated therein to be generally declaratory of existing customary law, defined the high seas as ‘all parts of the sea that are not included in the territorial sea or in the internal waters of a State’.1 On the other hand, Article 86, the first article of Part VII, entitled ‘High Seas’, of the 1982 Convention, as has already been noted, does not offer a definition, but stipulates:

‘The provisions of this Party apply to all parts of the sea that are not included in the exclusive economic zone, in the territorial sea or in the internal waters of a State, or in the archipelagic waters of an archipelagic State. This articles does not entail any abridgement of the freedoms enjoyed by all States in the exclusive economic zone in accordance with Article 58.’

Article 582 is the one that provides for the enjoyment by all states, within the exclusive economic zone, of ‘the freedoms referred to in Article 87 of navigation and overflight and of the laying of submarine cables and pipelines, and other internationally lawful uses of the sea related to these freedoms, such as those associated with the operation of ships, aircraft and submarine cables and pipelines, and compatible with the other provisions of this Convention’.3 The other freedoms of the high seas, to do not with navigation, overflight or communications, but with the getting of resources are, of course, in the 1982 Convention reserved to the coastal state, if they are within its exclusive economic zone. Further, the former freedom of scientific research is, by the 1982 Convention, no longer applicable in the exclusive economic zone.4 Another distinction imported (p. 731) by the 1982 Convention is that whereas, by its Article 88, ‘the high seas shall be reserved for peaceful purposes’, there is no corresponding provision in respect of that part of the high seas which is transformed into an exclusive economic zone. It should be noted, however, that in Article 311 of the 1982 Convention, which deals with its relation to other conventions and international agreements, it is provided in paragraph 1 that the 1982 Convention ‘shall prevail, as between States Parties, over the Geneva Conventions on the Law of the Sea of 29 April 1958’.


It is usual still to state this aspect of the freedom of the high seas in absolute terms; as, for example, in Art 2 of the 1958 Geneva Convention on the High Seas; or Art 89 of the 1982 Convention on the Law of the Sea. Yet there is a marginal aspect where it might seem to need qualification. A coastal state, by the adoption of a system of straight baselines for its territorial sea, or by the extension of the breadth of its territorial sea to the permitted maximum of 12 miles, can in conformity with international law enclose within its territorial sovereignty, waters which erstwhile were high seas; as indeed Norway had done in the Anglo-Norwegian Fisheries case. Nevertheless, this right of the coastal state extends only to waters which it has a right in international law thus to enclose. The scope of the right is thus governed by the general law. As the Judgment in the Anglo-Norwegian Fisheries case expressed it: ‘The delimitation of sea areas has always an international aspect; it cannot be dependent merely upon the will of the coastal State as expressed in its municipal law’ (ICJ Rep (1951), p 4 at 132).

Yet, for rights in the subsoil acquired by driving mines or piercing tunnels, see § 321; for continental shelf rights, see § 314. For former ideas about temporary ‘occupation’ of the high seas by vessels of a flag state, see the 8th ed of this vol, n 4 at p 589.

Article 2 of the 1958 Geneva Convention also expresses it less elaborately thus:

‘The high seas being open to all nations, no State may validly purport to subject any part of them to its sovereignty. Freedom of the high seas is exercised under the conditions laid down by these articles and by other rules of international law. It comprises, inter alia, both for coastal and non-coastal States:

(1)  Freedom of navigation;

(2)  Freedom of fishing;

(3)  Freedom to lay submarine cables and pipelines;

(4)  Freedom to fly over the high seas.

These freedoms, and others which are recognized by the general principles of international law, shall be exercised by all States with reasonable regard to the interests of other states in their exercise of the freedom of the high seas.’

See, however, Chierici v Merchant Navy Ministry (1969), ILR, 71, p 258 (Italy, Council of State) for a decision that the Geneva Conventions on the High Seas, Territorial Sea and Contiguous Zone did not create enforcible rights for individuals but only for states.

Ie the Part of the Convention dealing with the continental shelf; see § 317. For the general matter of submarine cables and pipelines, see Art 79 of the Convention.

Part XIII deals with marine scientific research; see § 348.

Ie the ‘Area’ of seabed and subsoil beyond national jurisdiction and dealt with in Part XI of the Convention; see § 350. This qualification of the freedom is controversial; for according to one view the freedom to explore and exploit the resources of the deep sea is also one of the freedoms in customary law, which the Convention could not prejudice for non-parties. However, ‘due regard’ is itself an ambivalent term.

See § 306.

That warships can on the open sea ask suspicious foreign merchantmen to show their flags has nothing to do with ceremonials, but with the supervision of the open sea in the interest of its safety. See § 293; and Lowe, Marine Policy, 10 (1986), p 171.

The freedom of navigation is reinforced by Art 90 which provides that: ‘Every State, whether coastal or land-locked, has the right to sail ships flying its flag on the high seas’. On freedom of navigation of merchant ships generally, see Hasselman, Die Freiheit der Handelsschiffahrt (1987).

Article 87.2 of the 1982 Convention. See also § 284, n 6.

There is, of course, a reciprocal obligation: see Art 78.2 of Part VI of the 1982 Geneva Convention, and also Art 5.1 of the Geneva Convention on the Continental Shelf, prohibiting ‘unjustifiable interference’ with the navigation, fishing, etc. Moreover, it is at any rate the long-established freedoms that should have priority. See eg YBILC (1951), ii, p 142: ‘Navigation and fishing must be considered as primary interests, so that the exploitation of the subsoil could not be permitted if it resulted in substantial interference with them. For example, in narrow channels essential for navigation, the claims of navigation should have priority over those of exploitation.’

See § 296.

See § 363.

See § 307.

See also YBILC (1956), ii, p 278, commenting on the draft article which became Art 2 of the 1958 Geneva Convention, cited in § 284, n 3:

‘The list of freedoms of the high seas contained in this article is not restrictive. The Commission has merely specified four of the main freedoms, but it is aware that there are other freedoms, such as freedom to undertake scientific research on the high seas … The Commission has not made specific mention of the freedom to explore or exploit the subsoil of the high seas. It considered that apart from the case of the exploitation or exploration of the soil or subsoil of a continental shelf … such exploitation had not yet assumed sufficient practical importance to justify special regulation.’

An example of a new freedom based upon a new technology might be the deployment of Ocean Data Acquisition Systems (ODAS), which is sufficiently important to require regulation: see UNESCO-IMCO SC-72/CONF 85/5, 85/6, 85/7 and 85/8.

10  See Part X, entitled ‘Right of Access of Land-locked States to and from the Sea and Freedom of Transit’. See also § 336.

On the legal position of land-locked states generally, see Caflisch, BY, 48 (1978), pp 71–100.

11  See ICJ Rep [1974] 253 and 457. For naval manoeuvres and the EEZ see § 332.

Article 1.

See § 330.

One of the controversies at UNCLOS III was whether the exclusive economic zone was a part of the high seas in which the coastal state has an exclusive resource jurisdiction, or whether it is part of the domain of the coastal state in which all states have certain freedoms. It will be appreciated that Art 86 is drafted in terms which reflect this controversy. In any event the view that the exclusive economic zone is sui generis is unexceptionable.

See § 349.