A foreign ship may cross another State’s territorial sea without asking, and that right lasts only while its passage stays innocent under article 19 of UNCLOS. Hot pursuit is what a coastal State may do once the ship abuses that right and runs for open water.
Innocence and pursuit are each defined in a few lines of treaty text. Passage is innocent, article 19(1) says, “so long as it is not prejudicial to the peace, good order or security of the coastal State”, and article 17 gives the right to “ships of all States, whether coastal or land-locked”. Pursuit turns on where it starts, because article 111(1) requires that it “be commenced when the foreign ship or one of its boats is within the internal waters, the archipelagic waters, the territorial sea or the contiguous zone of the pursuing State”.
That wording leaves three things open. It fixes no number of conditions for a lawful pursuit, which is why competing lists of five and six circulate with no authority behind them. It says nothing express about warships, so States have read the same four words, “ships of all States”, in opposite directions for four decades. And the two doctrines are joined at a hinge that is rarely stated, because the water in which a pursuit may lawfully begin is the same water in which the passage right was abused.
A Special Chamber of the International Tribunal for the Law of the Sea decided a case on that boundary in 2026. Equatorial Guinea, defending its apprehension of a Marshall Islands tanker in a third State’s exclusive economic zone, listed hot pursuit among the recognised limits on freedom of navigation, and the Marshall Islands answered that “This was not a hot pursuit operation. … The vessel was not trying to flee.” The Special Chamber held the interception unlawful under articles 87(1), 90 and 92(1) of the Convention and never reached article 111 at all, which leaves the last condition-by-condition ruling on hot pursuit where it has stood since 2015.
Where a pursuit has to begin is easiest to see in an incident that stopped one step short of needing one. In January 2026 an Indian Coast Guard ship sighted a Pakistani fishing boat, the Al-Madina, inside Indian waters near the International Maritime Boundary Line in the Arabian Sea.
The boat was challenged, and on the Government’s own account it then attempted to flee towards the Pakistan side. The Coast Guard ship intercepted and boarded it while it was still in Indian waters, found nine crew on board, and towed it to Porbandar for rummaging and joint interrogation.
Two legal consequences follow from where that boarding happened. Because the boat was stopped inside India’s own territorial waters, the Coast Guard was acting under Indian sovereignty and article 111 was never engaged at all. Had the boat instead reached Pakistan’s territorial sea, article 111(3) would have extinguished any pursuit the moment it crossed, however correctly India had acted up to that point.
Innocent passage under UNCLOS while a foreign ship crosses the territorial sea
Innocent passage belongs to the ships of every State, and article 17 of UNCLOS grants it in exactly those terms: “ships of all States, whether coastal or land-locked, enjoy the right of innocent passage through the territorial sea.” The territorial sea runs up to twelve nautical miles from the baseline, and inside it the coastal State holds full sovereignty, subject to this one standing servitude in favour of foreign navigation. No permission is sought for passage and none is given, which is what separates the territorial sea from internal waters and from the other maritime zones a State controls.
Two separate gates have to be passed before a ship can claim the right, and most accounts run them together. The first gate is whether the voyage is “passage” at all. Article 18 defines passage as navigation for the purpose of traversing the territorial sea, or of proceeding to or from internal waters or a port call, and it requires that passage be “continuous and expeditious”. Stopping and anchoring are allowed only so far as they are incidental to ordinary navigation, or are rendered necessary by force majeure or distress, or are for the purpose of rendering assistance to persons, ships or aircraft in danger or distress.
The second gate is the character of that passage, and article 19(1) supplies the standard in a single line: passage is innocent “so long as it is not prejudicial to the peace, good order or security of the coastal State”. The two gates catch different ships. A vessel that loiters off the coast for a fortnight fails at article 18 before anyone reaches article 19, while a vessel that transits in a straight line at fifteen knots with its cameras trained on a naval base satisfies article 18 and fails article 19.
Twelve activities in article 19(2) that end innocent passage
Twelve lettered activities in article 19(2) make a passage prejudicial to the peace, good order or security of the coastal State. The list converts an open-textured standard into something an officer can apply from the bridge. Passage is to be considered prejudicial if in the territorial sea the foreign ship engages in any of the following:
- (a) any threat or use of force against the sovereignty, territorial integrity or political independence of the coastal State, or in any other manner in violation of the principles of international law embodied in the Charter of the United Nations;
- (b) any exercise or practice with weapons of any kind;
- (c) any act aimed at collecting information to the prejudice of the defence or security of the coastal State;
- (d) any act of propaganda aimed at affecting the defence or security of the coastal State;
- (e) the launching, landing or taking on board of any aircraft;
- (f) the launching, landing or taking on board of any military device;
- (g) the loading or unloading of any commodity, currency or person contrary to the customs, fiscal, immigration or sanitary laws and regulations of the coastal State;
- (h) any act of wilful and serious pollution contrary to this Convention;
- (i) any fishing activities;
- (j) the carrying out of research or survey activities;
- (k) any act aimed at interfering with any systems of communication or any other facilities or installations of the coastal State;
- (l) any other activity not having a direct bearing on passage.
Two features of that list decide most real disputes. The activities are things the ship does, not things the ship is, so nothing in article 19(2) is triggered by a vessel’s status as a warship. And the heads are specific enough to be argued about on facts: head (c) is what an intelligence-gathering transit runs into, head (e) covers a helicopter or drone sortie launched from the deck, and head (i) is why a trawler that shoots its nets in a foreign territorial sea has forfeited the right before any fisheries prosecution begins.
Head (l) then reopens what the first eleven heads close. It covers “any other activity not having a direct bearing on passage”, which is a residual clause sitting at the end of an otherwise exhaustive list. So article 19(2) is a closed list of twelve heads whose last head is open-textured.
Both of the shorthand descriptions in circulation are inaccurate as a result. It is not a merely illustrative list, because eleven of the heads are specific and closed. It is also not a closed list in the sense that nothing outside those eleven can ever count, because head (l) exists to catch what the drafters did not name.
Coastal State powers over a foreign ship in innocent passage
A coastal State’s powers over a ship in innocent passage are regulatory before they are coercive. Article 21 lets the State legislate on a defined set of subjects and article 22 lets it route traffic into sea lanes, while article 24 limits what those laws may do in practice. The coercive power arrives only in article 25(1), under which the State “may take the necessary steps in its territorial sea to prevent passage which is not innocent”.
Article 25(1) is also the bridge from one doctrine in this article to the other. While the offending ship stays inside the territorial sea, the coastal State acts under its own sovereignty and needs no pursuit doctrine at all. Once the ship runs for open water, those same necessary steps have to find a justification in article 111 instead, and the ship’s abuse of the passage right is what supplies the “good reason to believe” that article 111(1) requires.
Laws a coastal State may enforce against a ship in innocent passage
The laws a coastal State may enforce against a ship in innocent passage are confined to eight subject-matters, and article 21(1) lists them exhaustively: safety of navigation and the regulation of maritime traffic, protection of navigational aids and facilities, protection of cables and pipelines, conservation of the living resources of the sea, prevention of infringement of fisheries laws, preservation of the environment and the control of pollution, marine scientific research and hydrographic surveys, and prevention of infringement of customs, fiscal, immigration or sanitary laws. Article 21(2) then bars those laws from reaching the design, construction, manning or equipment of foreign ships unless they give effect to generally accepted international rules, and article 21(3) requires due publicity.
Article 22 adds a routing power rather than a prohibiting one. A coastal State may require foreign ships in innocent passage to use designated sea lanes and traffic separation schemes where that is necessary for the safety of navigation, and it may confine tankers, nuclear-powered ships and ships carrying dangerous or noxious cargo to those lanes. It must take the recommendations of the competent international organisation into account when it designates them.
Article 24 then states the limits from the other direction, and they are the provisions a foreign flag State reaches for first. The coastal State must not hamper innocent passage except in accordance with the Convention, must not impose requirements “which have the practical effect of denying or impairing the right of innocent passage”, and must not discriminate “in form or in fact” against the ships of any State. Prior notification by a foreign warship appears nowhere among the eight heads in article 21(1), and a notice requirement is at least arguable as a requirement with the practical effect of impairing the right under article 24(1)(a). No tribunal has settled either point.
Criminal jurisdiction on board a passing ship runs on a different provision, and its modal verbs are load-bearing. Article 27(1) provides that the coastal State’s criminal jurisdiction “should not” be exercised on board a foreign ship passing through the territorial sea to arrest a person or investigate a crime committed on board during the passage. It then opens four gateways: where the consequences of the crime extend to the coastal State, where the crime is of a kind to disturb the peace of the country or the good order of the territorial sea, where the master or a flag State consular officer has requested assistance, or where the measures are necessary to suppress illicit traffic in narcotic drugs or psychotropic substances.
Article 27(5) by contrast says the coastal State “may not” take steps on board in connection with a crime committed before the ship entered the territorial sea, where the ship is merely passing through from a foreign port. One paragraph states a strong recommendation and the other states a prohibition, which is a deliberate drafting distinction rather than loose usage.
Warships, submarines and sovereign immunity under articles 29 to 32
Warships are not carved out of the innocent passage regime by any express words, and the strongest textual argument that they hold the right comes from where articles 29 to 32 sit in the Convention. All four are inside Subsection C of the section headed “Innocent passage in the territorial sea”. Article 30 provides that where a warship does not comply with the coastal State’s laws concerning passage and disregards a request for compliance, the coastal State “may require it to leave the territorial sea immediately”, which is a remedy that presupposes the warship was in passage. Article 31 makes the flag State internationally responsible for loss or damage caused by such non-compliance, and article 32 preserves the immunities of warships except as articles 30 and 31 provide.
Article 29 supplies the definition, and it has four cumulative elements. A warship belongs to the armed forces of a State, bears the external marks distinguishing the ships of its nationality, is under the command of an officer duly commissioned by the government and whose name appears in the appropriate service list, and is manned by a crew under regular armed forces discipline.
Submarines get a rule of their own in article 20, which requires them to navigate on the surface and to show their flag in the territorial sea. That rule is frequently stated backwards. Surfacing is the territorial sea rule, and in transit passage through straits used for international navigation submerged transit in normal mode is the accepted position.
Neither the definition in article 29 nor the submarine rule settles whether a warship can be required to give notice before it enters, and State practice on that question is divided. India, China and a substantial group of other States require prior notification or authorisation; the United States, the United Kingdom and others maintain that article 17 admits of no such condition. The International Court of Justice came closest to the question in Corfu Channel in 1949, holding that States in peacetime may send warships through straits used for international navigation without the previous authorisation of the coastal State, “provided that the passage is innocent”. Albania, the Court added, would have been justified in regulating such passage “but not in prohibiting such passage or in subjecting it to the requirement of special authorization”.
Two qualifications attach to that holding. The right the Court recognised was the customary straits right rather than the territorial sea regime later codified in articles 17 to 19. And the Court expressly declined to consider “whether States under international law have a right to send warships in time of peace through territorial waters not included in a strait”, which is the very question a prior-notification rule turns on.
Hot pursuit under UNCLOS article 111 after the ship refuses to stop
Hot pursuit has to begin while the offending ship is still inside the coastal State’s own waters, and it is lawful only if every condition in article 111 was satisfied at that moment. The International Tribunal for the Law of the Sea stated the governing principle in M/V “Saiga” (No. 2) on 1 July 1999: “the conditions for the exercise of the right of hot pursuit under article 111 of the Convention are cumulative; each of them has to be satisfied for the pursuit to be legitimate under the Convention.” Guinea failed several of them, and the Tribunal awarded Saint Vincent and the Grenadines US$ 2,123,357 in compensation. Both that case and the arbitrations discussed below were heard through the dispute settlement machinery of UNCLOS.
No tribunal has ever fixed the number of those conditions, and this is where most published accounts go wrong. Saiga says the conditions are cumulative and gives no count at all. The Annex VII tribunal in The Arctic Sunrise Arbitration grouped them into four for the purposes of its own analysis, speaking of a first prerequisite, of second and third conditions, and of a fourth condition. Lists of five or six conditions circulate widely with no authority attached to them, and an answer that attributes a specific number to ITLOS is wrong on the source.
Two accurate ways of stating the test are therefore available. One is the four-condition walk that an arbitral tribunal actually applied to a live set of facts. The other is the full enumeration of every discrete requirement in the text, tied to the sub-paragraph that imposes it.
Four conditions the Arctic Sunrise tribunal applied to a hot pursuit claim
Four conditions were applied in turn by the tribunal in The Arctic Sunrise Arbitration, decided on 14 August 2015, and the pursuit failed on the last of them. Russia had boarded and seized the Netherlands-flagged Arctic Sunrise in its exclusive economic zone after protesters approached the Prirazlomnaya platform, and the tribunal held that a boarding on suspicion of the offences alleged “finds a basis under international law only if the requirements of hot pursuit are satisfied”. Russia did not take part in the proceedings at any stage.
The first condition is that the competent authorities have good reason to believe the ship has violated laws applicable in that area, and Russia satisfied it. The tribunal proceeded on the assumption that a 500-metre safety zone had been validly established around the platform, while noting that article 60(4) does not automatically create such a zone around every installation in every State’s exclusive economic zone. On that assumption, Russia would have had good reason to believe that the ship’s rigid-hulled inflatable boats had breached the navigation prohibition.
The second and third conditions concern the signal to stop and the pursued ship’s location when it is given, and they produced the most useful holding in the modern case law. The Netherlands argued that a VHF radio message is not a “visual or auditory signal” within article 111(4). The tribunal disagreed, reasoning that the parameters of the right “must be interpreted in the light of their object and purpose, having regard to the modern use of technology” and that the object of the signal rule “is to ensure that the pursued ship is made aware of the pursuit”. It relied on the SOLAS requirement that ships monitor VHF channel 16, noted that the two vessels were about three nautical miles apart, and held the first radio order to stop to be a valid auditory signal.
Two refinements inside that holding matter as much as the holding itself. A stop order given to the inflatable boats rather than to the mother ship would not have been valid, because the Convention requires that stop orders be given to the main ship that is to be pursued. And although the tribunal found the first stop order was probably given a minute or two after the last boat had left the 500-metre zone, it held that article 111(4)’s “satisfied itself by such practicable means as may be available” test is set out less stringently than article 111(1), and should be looked at from the perspective of the pursuing ship rather than with the full benefit of hindsight.
The fourth condition is continuity, and it is where Russia lost. For roughly three hours after the first stop order the pursuing vessel Ladoga behaved consistently with a pursuit, issuing repeated orders, firing warning shots and attempting a boarding. It then unloaded its gun mounts, stopped issuing orders, and for some 36 hours simply shadowed the Arctic Sunrise, at one point allowing a boat to deliver clothing, food and medicine. The tribunal concluded that the pursuit had been interrupted and that the right of hot pursuit “cannot serve as the legal basis for the boarding, seizure, and detention of the Arctic Sunrise“.
Eight cumulative requirements for hot pursuit in the text of article 111
Eight discrete requirements are imposed by the text of article 111 itself, and no tribunal has adopted this enumeration as such. Each is tied below to the sentence that imposes it:
- The belief is held by the competent authorities of the coastal State, not by any official and not by the pursuing crew alone, under article 111(1), sentence 1.
- Those authorities have good reason to believe the ship has violated the laws and regulations of that State, under article 111(1), sentence 1, which is a higher threshold than suspicion.
- Pursuit commences while the ship, or one of its boats, is within internal waters, archipelagic waters, the territorial sea or the contiguous zone, under article 111(1), sentence 2.
- Where the ship is in the contiguous zone, the violation is of the rights for the protection of which that zone was established, under article 111(1), sentence 4, and where the basis is the exclusive economic zone or continental shelf, the law violated is one applicable there in accordance with the Convention, under article 111(2).
- The pursuit is not interrupted once it continues outside the territorial sea or contiguous zone, under article 111(1), sentence 2.
- The pursuing ship has satisfied itself, by such practicable means as may be available, that the pursued ship or a craft working as a team with it was within the relevant limits, under article 111(4), sentence 1.
- A visual or auditory signal to stop is given at a distance enabling it to be seen or heard, before pursuit commences, under article 111(4), sentence 2.
- The pursuit is conducted only by warships, military aircraft, or other ships or aircraft clearly marked and identifiable as being on government service and authorised to that effect, under article 111(5).
Two extensions apply beyond those eight requirements. Article 111(2) applies the right mutatis mutandis to violations in the exclusive economic zone or on the continental shelf, including safety zones around continental shelf installations, which is why the common statement that a pursuit cannot begin in the exclusive economic zone is incomplete rather than merely imprecise. Article 111(6) governs pursuit by aircraft, and it requires the aircraft that gives the order to stop to pursue the ship itself until a summoned ship or aircraft takes over, adding that mere sighting never justifies an arrest outside the territorial sea.
One sentence in article 111 is regularly listed as a condition when it does the opposite. Article 111(1), sentence 3, provides that it is not necessary for the ship giving the order to stop to be itself within the territorial sea or the contiguous zone when the foreign ship receives it. That is a relaxation in favour of the pursuing State, and a page that records “the pursuing vessel must be inside the zone” among the requirements has inverted the text.
Termination of hot pursuit and the compensation that follows an unlawful arrest
Termination is governed by a single sentence, and it is absolute. Article 111(3) provides that the right of hot pursuit “ceases as soon as the ship pursued enters the territorial sea of its own State or of a third State”, so a pursuing warship that follows the fleeing vessel across that line is no longer exercising any Convention right. Nothing in article 111 lets a coastal State follow a ship all the way into shelter, and the pursuit does not revive if the ship leaves again.
Pursuit of pirates works differently, and the two are constantly conflated. Hot pursuit is a coastal State’s remedy against a ship that has violated that State’s own laws and is running, which is why it needs a commencement zone and unbroken continuity. Repression of piracy on the high seas rests on universal jurisdiction under articles 105 and 110, where every State may seize a pirate ship with no pursuit, no zone and no continuity requirement at all, a basis examined separately in this blog’s treatment of universal jurisdiction under international law. If the offence is high-seas piracy, article 111 is never needed; if article 111 is needed, the offence was not high-seas piracy.
Interruption of pursuit in Saiga and Arctic Sunrise
Interruption has defeated the coastal State in both of the leading cases, and in each it was a single operational decision that did the damage. In Saiga, Guinea sent patrol boat P35 northwards on 26 October 1997 to look for the tanker and then recalled it on learning that the Saiga had changed course. ITLOS held that this recall “constituted a clear interruption of any pursuit, whatever legal basis might have existed for its commencement in the first place”.
The Arctic Sunrise tribunal reached the same result on very different facts. There the pursuing ship never turned back; it simply stopped behaving like a pursuer, standing off for some 36 hours with its gun mounts unloaded and no further orders issued. The tribunal held that conduct “is not consistent with continuous pursuit, the final objective of which would have been to board, as soon as possible, the pursued ship”, and added that the Arctic Sunrise had for its part remained in the area and had not tried to flee.
Guinea failed on more than continuity, and the other failures show how little margin article 111 leaves. ITLOS found that when the order for the joint customs and navy mission was issued the Guinean authorities “could have had no more than a suspicion” that a tanker had violated Guinean law, which is below the good reason to believe threshold. It found that no visual or auditory signals to stop could have been given on the first leg, and that the evidence did not support Guinea’s claim that the required signals were given before the alleged pursuit commenced on the second. It then held that no Guinean laws applicable in accordance with the Convention had been violated at all, so there was no legal basis for a pursuit in the first place.
Force during a pursuit and the compensation owed under article 111(8)
Force is not one of the conditions in article 111, and treating it as one misplaces the analysis. ITLOS held in Saiga that the Convention contains no express provision on the use of force in arresting ships, so general international law applies through article 293, and that law “requires that the use of force must be avoided as far as possible and, where force is unavoidable, it must not go beyond what is reasonable and necessary in the circumstances. Considerations of humanity must apply in the law of the sea”. The Tribunal set out an escalation ladder: internationally recognised signals to stop first, then a range of further actions including firing shots across the bows, and only then force as a last resort, with due warning and every effort to ensure that life is not endangered.
Two twentieth-century decisions are usually cited on this point, and both are routinely described wrongly. In The “I’m Alone”, the Commissioners reported in January 1935 that the intentional sinking of the vessel “could not be justified by any principle of international law”, awarded nothing for the ship or cargo because it was in truth United States owned, and directed an apology and US$ 25,000 to Canada as a material amend together with indemnities for the captain and crew.
What the Commissioners never did was decide the continuity question. They recorded in 1933 that they were “not in agreement as to the proper answer, nor have they reached a final disagreement on the matter”. The Final Report then states that “Only questions numbered One and Three and the answers given thereto are now material”, the hot pursuit question having dropped out of the reference altogether.
The Red Crusader is treated as a hot pursuit authority still more often, and the report does not mention pursuit at all. The Commission of Enquiry reported in March 1962 that the commanding officer of the Danish fishery protection vessel had exceeded the legitimate use of armed force on two counts, by “firing without warning of solid gun-shot” and by “creating danger to human life on board the ‘Red Crusader’ without proved necessity”. It added that the trawler’s escape and the seclusion of the Danish officer on board “cannot justify such a violent action”, and that other means should have been attempted. The case is authority on proportionality in maritime law enforcement, which is precisely how ITLOS used it in Saiga.
The price of getting any of this wrong is set by article 111(8), which provides that a ship stopped or arrested outside the territorial sea in circumstances that do not justify hot pursuit “shall be compensated for any loss or damage that may have been thereby sustained”. The sums are no longer nominal, and Guinea was ordered to pay US$ 2,123,357 in Saiga.
The Arctic Sunrise tribunal went further in its award of 10 July 2017, ordering Russia to pay four heads of damage. The largest two were EUR 1,695,126.18 for damage to the vessel and EUR 2,461,935.43 for the measures taken against those detained, and the award itself states no single total.
Innocent passage and hot pursuit under UNCLOS in Indian maritime law
India legislated on these questions six years before UNCLOS was adopted, and the relevant section has not been amended since. The Territorial Waters, Continental Shelf, Exclusive Economic Zone and Other Maritime Zones Act, 1976 fixes the territorial waters at twelve nautical miles in section 3, the contiguous zone at twenty-four in section 5 and the exclusive economic zone at two hundred in section 7. India signed the Convention in 1982 and ratified it on 29 June 1995.
Two features of that architecture separate India from the Convention it later ratified, and both matter for enforcement at sea. Section 4 handles innocent passage on a structurally different scheme from article 17, and Indian authority beyond the territorial waters runs through notification rather than through article 111. The broader framework that sits around these provisions is set out in this blog’s account of UNCLOS and Indian maritime security.
Prior notice for foreign warships under section 4(2) of the 1976 Act
Prior notice, and not prior permission, is what India requires from a foreign warship, and the distinction is garbled in both directions in the secondary literature. Section 4(2) of the 1976 Act provides that foreign warships including submarines and other underwater vehicles “may enter or pass through the territorial waters after giving prior notice to the Central Government”, with a proviso that submarines and other underwater vehicles navigate on the surface and show their flag. A State that required authorisation would be asserting a power to refuse; India asserts a power to be told.
Section 4(1) does something more far-reaching than adding a notice requirement. It grants the right of innocent passage to “all foreign ships (other than warships including submarines and other underwater vehicles)”, so warships are excluded from the right altogether and then given a separate, conditioned entitlement to enter or pass through by section 4(2). That is a different structure from article 17, which grants the right to ships of all States and makes no distinction by vessel type. The Explanation to section 4(1) reproduces the article 19(1) standard of peace, good order and security, but the twelve heads of article 19(2) appear nowhere in the Act.
India’s declaration on ratifying UNCLOS is regularly said to reserve this position, and it does not. The declaration has two limbs: the first reserves the right to make the declarations provided for in articles 287 and 298 on dispute settlement, and the second records India’s understanding that the Convention does not authorise other States to carry out military exercises or manoeuvres in the exclusive economic zone or on the continental shelf without coastal State consent. Neither limb mentions warships in the territorial sea, innocent passage or prior notification, and article 309 bars reservations in any event. So the warship notice rule stands on domestic law alone, and the objection India raised to a United States naval transit near Lakshadweep in 2021 rested on the second limb about the exclusive economic zone, which is a different question from innocent passage through the twelve-mile belt.
Enforcement chain that gives India its powers at sea without hot pursuit
Enforcement authority in India’s maritime zones is derivative rather than original, and tracing the chain answers most practical questions about what the Coast Guard may do. Sections 5(5) and 7(7) of the 1976 Act empower the Central Government to extend any enactment to the contiguous zone or the exclusive economic zone by notification in the Official Gazette, whereupon the enactment takes effect as if the zone were part of the territory of India. The Supreme Court construed that mechanism in Aban Loyd Chiles Offshore Ltd. v. Union of India in 2008, holding that Indian enactments do not apply automatically beyond the territorial waters and that the statutory fiction operates for limited purposes only.
The Coast Guard Act, 1978 supplies no hot pursuit power and no general power of arrest over foreign vessels. Section 14(1) makes it the Coast Guard’s duty to protect India’s maritime and other national interests in the maritime zones, and section 14(2)(e) states the enforcement function as “enforcing the provisions of such enactments as are for the time being in force in the maritime zones”. Chapter IV of the Act, headed Offences, deals with internal service discipline and is tried by Coast Guard Courts. The arrest power in any given operation therefore comes from the specific enactment that has been extended seaward, which is the route the Supreme Court followed in the Enrica Lexie proceedings in 2012, when it located Indian jurisdiction in the extension of the Indian Penal Code by the Ministry of Home Affairs notification of 27 August 1981.
Two exposures sit inside that chain, and the first is textual. Section 5(4)(a) of the 1976 Act adds “the security of India” to the interests India may protect in its contiguous zone, where article 33(1) of the Convention lists only customs, fiscal, immigration and sanitary interests. A contiguous zone pursuit launched on a security ground would therefore rest on an interest the Convention does not recognise for that zone, which is what the final sentence of article 111(1) tests.
The second exposure runs the other way, because it removes the occasion for a pursuit at all. The Maritime Anti-Piracy Act, 2022 defines the high seas to include India’s own exclusive economic zone, and section 7(1) allows authorised personnel to board a ship “either generally or on suspicion” of piracy, with no pursuit, no commencement zone and no signal. An Indian piracy prosecution therefore never has to engage article 111. The arbitral tribunal in the Enrica Lexie case was invited to rule on the compatibility of the 1976 Act with the Convention and held unanimously that there was no need to address the question, so the Act has never been tested internationally.
Frequently asked questions
Do warships enjoy the right of innocent passage under UNCLOS?
The Convention does not answer this in express words, and State practice is divided. Article 17 grants the right to “ships of all States” without distinguishing by vessel type, and articles 30 and 31 presuppose that a warship can be in passage, because article 30 gives the coastal State the single remedy of requiring a non-compliant warship to leave. Against that, a substantial group of States including India and China impose notification or authorisation requirements. The International Court of Justice in Corfu Channel recognised a right of warship passage through straits used for international navigation provided the passage is innocent, and expressly reserved the question for territorial waters outside a strait.
Does India require prior permission or only prior notice for foreign warships?
India requires prior notice rather than prior permission, and the two are not interchangeable. Section 4(2) of the Territorial Waters, Continental Shelf, Exclusive Economic Zone and Other Maritime Zones Act, 1976 allows foreign warships to enter or pass through the territorial waters “after giving prior notice to the Central Government”, which is not a requirement of permission and carries no power to refuse. Section 4(1) separately excludes warships from the right of innocent passage that it grants to all other foreign ships. India’s 1995 declaration on ratifying UNCLOS contains no prior-notification reservation, so the rule rests on domestic law alone.
Can a coast guard chase a ship into international waters?
A coast guard vessel can continue a pursuit onto the high seas, but only if it is properly authorised and only if the pursuit was lawfully commenced. Article 111(5) restricts the right to warships, military aircraft, and other ships or aircraft clearly marked and identifiable as being on government service and authorised for the purpose, which covers a coast guard ship. The pursuit must have started while the offending ship or one of its boats was inside the pursuing State’s internal waters, archipelagic waters, territorial sea or contiguous zone, or, under article 111(2), in its exclusive economic zone or over its continental shelf, and it must not have been interrupted.
When does the right of hot pursuit end?
The right ends the moment the pursued ship enters the territorial sea of its own State or of a third State, under article 111(3). It also ends if the pursuit is interrupted before that, which is what happened in M/V “Saiga” (No. 2) when Guinea recalled its patrol boat, and in The Arctic Sunrise Arbitration when the pursuing vessel spent some 36 hours shadowing the ship without issuing further orders. Where a ship is stopped or arrested outside the territorial sea in circumstances that do not justify hot pursuit, article 111(8) requires that it be compensated for any loss or damage.
Is hot pursuit the same as chasing pirates on the high seas?
Hot pursuit and the repression of piracy are different doctrines with different triggers. Hot pursuit is a coastal State’s remedy against a ship that has violated that State’s laws and is fleeing, and it depends on a commencement zone, a signal to stop and unbroken continuity. Repression of piracy on the high seas rests on universal jurisdiction under articles 105 and 110, under which any State may seize a pirate ship without any pursuit at all. India’s Maritime Anti-Piracy Act, 2022 reflects that difference, because section 7(1) lets authorised personnel board a suspected pirate ship “either generally or on suspicion” with no pursuit requirement.
Must submarines surface in the territorial sea?
Submarines and other underwater vehicles must navigate on the surface and show their flag in the territorial sea, under article 20. Detection has nothing to do with it; a submerged transit is unlawful whether or not the coastal State notices. The rule is often stated the wrong way round for straits, where transit passage under Part III is generally accepted to permit passage in normal mode, which for a submarine means submerged. India applies the surfacing requirement to foreign submarines through the proviso to section 4(2) of the 1976 Act.
References
- United Nations Convention on the Law of the Sea, 1982, Part II, articles cited being 17, 18, 19, 20, 21, 22, 24, 25, 27, 28, 29, 30, 31, 32 and 33. https://www.un.org/depts/los/convention_agreements/texts/unclos/part2.htm
- United Nations Convention on the Law of the Sea, 1982, Part VII, article cited being 111. https://www.un.org/depts/los/convention_agreements/texts/unclos/part7.htm
- M/V “Saiga” (No. 2) (Saint Vincent and the Grenadines v. Guinea), International Tribunal for the Law of the Sea, judgment of 1 July 1999, ITLOS Reports 1999, p. 10, paragraphs cited being 146 to 158 and 183. https://www.itlos.org/fileadmin/itlos/documents/cases/case_no_2/published/C2-J-1_Jul_99.pdf
- The Arctic Sunrise Arbitration (Netherlands v. Russian Federation), PCA Case No. 2014-02, Award on the Merits of 14 August 2015, paragraphs cited being 244 to 278. https://pcacases.com/web/sendAttach/1438
- The Arctic Sunrise Arbitration (Netherlands v. Russian Federation), Award on Compensation of 10 July 2017. https://pcacases.com/web/sendAttach/2214
- The M/T “Heroic Idun” (No. 2) Case (Marshall Islands/Equatorial Guinea), International Tribunal for the Law of the Sea Special Chamber, judgment of 27 May 2026, ITLOS Case No. 32. https://www.itlos.org/fileadmin/itlos/documents/cases/32/judgment/C32_Judgment_27.05.2026_orig.pdf
- Corfu Channel (United Kingdom v. Albania), International Court of Justice, merits judgment of 9 April 1949, ICJ Reports 1949, p. 4. https://www.icj-cij.org/case/1
- The S.S. “I’m Alone” (Canada v. United States), Joint Interim Report of 30 June 1933 and Joint Final Report of 5 January 1935, UNRIAA vol. III, pp. 1609 to 1618. https://legal.un.org/riaa/cases/vol_III/1609-1618.pdf
- The Red Crusader, Commission of Enquiry (Denmark and United Kingdom), report of 23 March 1962, UNRIAA vol. XXIX, pp. 521 to 539. https://legal.un.org/riaa/cases/vol_XXIX/521-539.pdf
- The “Enrica Lexie” Incident (Italy v. India), PCA Case No. 2015-28, award of 21 May 2020, extracts released 2 July 2020. https://pcacases.com/web/sendAttach/16500
- The Territorial Waters, Continental Shelf, Exclusive Economic Zone and Other Maritime Zones Act, 1976 (Act 80 of 1976), sections cited being 3, 4, 5 and 7. https://www.un.org/depts/los/LEGISLATIONANDTREATIES/PDFFILES/IND_1976_Act.pdf
- The Coast Guard Act, 1978 (Act 30 of 1978), section cited being 14. https://mod.gov.in/sites/default/files/Coast%20Guard%20Act,%201978.pdf
- The Maritime Anti-Piracy Act, 2022 (Act 3 of 2023), in force 22 February 2023, sections cited being 1, 2 and 7. https://natlex.ilo.org/dyn/natlex2/natlex2/files/download/117630/THE%20MARITIME%20ANTI-PIRACY%20ACT,%202022%20INDIA.pdf
- India’s declaration on ratification of the United Nations Convention on the Law of the Sea, 29 June 1995, United Nations Treaty Collection, Chapter XXI-6. https://treaties.un.org/Pages/ViewDetailsIII.aspx?src=TREATY&mtdsg_no=XXI-6&chapter=21&Temp=mtdsg3&clang=_en
- Aban Loyd Chiles Offshore Ltd. v. Union of India, Supreme Court of India, judgment of 11 April 2008, (2008) 11 SCC 439. https://indiankanoon.org/doc/1530670/
- Republic of Italy through Ambassador v. Union of India, Supreme Court of India, judgment of 4 September 2012. https://indiankanoon.org/doc/78409161/
- Indian Coast Guard interception of the fishing boat Al-Madina, News on AIR, Prasar Bharati, 16 January 2026. https://www.newsonair.gov.in/indian-coast-guard-intercepts-pakistani-boat-inside-indian-waters-in-arabian-sea
This article is for informational and educational purposes only and does not constitute legal advice. Readers should consult a qualified advocate before acting on any point discussed here.