Contiguous Zone

Introduction

The contiguous zone is a maritime zone extending beyond the territorial sea in which a coastal State may exercise limited control for specific enforcement purposes.

It is governed principally by Article 33 of the United Nations Convention on the Law of the Sea (UNCLOS).

Unlike the territorial sea, the contiguous zone is not subject to the full sovereignty of the coastal State. Instead, the coastal State has limited powers to prevent and punish violations of certain laws within its territory or territorial sea.

The four areas in which the coastal State may exercise control are:

• customs
• fiscal
• immigration
• sanitary

The basic formula is:

Baseline → 12 nm Territorial Sea → Up to 24 nm Contiguous Zone

Meaning of Contiguous Zone

The contiguous zone is a zone of sea contiguous to the territorial sea in which the coastal State can exercise specified enforcement powers.

The term “contiguous” means adjacent or adjoining.

It is therefore located immediately beyond the territorial sea.

Legal Basis

The principal provision is:

Article 33 UNCLOS – Contiguous Zone

Under Article 33, a coastal State may exercise the control necessary to:

prevent infringement of its:

• customs laws;
• fiscal laws;
• immigration laws;
• sanitary laws;

within its territory or territorial sea.

It may also exercise control to punish infringement of those laws committed within its territory or territorial sea.

Breadth of the Contiguous Zone

Under Article 33(2), the contiguous zone may extend to a maximum of:

24 nautical miles from the baselines

This is important because the 24 nautical miles are measured from the baseline, not from the outer edge of the territorial sea.

Therefore:

Baseline → 12 nm Territorial Sea

Baseline → 24 nm Maximum Contiguous Zone

The contiguous zone therefore ordinarily consists of the area between:

12 nm and 24 nm from the baseline.

Maritime-Zone Diagram

Coast

↓

Baseline

↓

0–12 nm → Territorial Sea

↓

12–24 nm → Contiguous Zone

↓

Beyond 24 nm → EEZ / Other Applicable Maritime Regime

Territorial Sea and Contiguous Zone

The most important distinction is the nature of the coastal State’s authority.

Territorial Sea

The coastal State exercises sovereignty.

Contiguous Zone

The coastal State exercises limited enforcement control.

Therefore:

Territorial Sea = Sovereignty

Contiguous Zone = Limited Control

Nature of Coastal-State Rights

The coastal State does not acquire full territorial sovereignty over the contiguous zone.

Its powers are functional and limited to the purposes specified in Article 33.

The coastal State cannot simply treat the contiguous zone as an extension of its territory.

Four Areas of Control

Customs Control

The coastal State may prevent or punish violations of its customs laws.

This can concern matters such as:

• smuggling;
• illegal importation;
• evasion of customs duties;
• prohibited goods.

The purpose is to protect the State’s customs regime within its territory and territorial sea.

Fiscal Control

The coastal State may prevent or punish infringement of its fiscal laws.

Fiscal laws generally concern:

• taxation;
• duties;
• revenue-related matters.

The power is directed toward protecting the State’s fiscal interests.

Immigration Control

The coastal State may prevent or punish infringement of its immigration laws.

This can involve:

• illegal entry;
• unauthorised migration;
• immigration violations;
• attempts to evade immigration controls.

The purpose is to protect immigration controls applicable within the territory and territorial sea.

Sanitary Control

The coastal State may prevent or punish infringement of its sanitary laws.

Sanitary measures can concern:

• public health;
• quarantine;
• disease control;
• sanitary conditions affecting entry into the State.

Prevention and Punishment

Article 33 gives the coastal State two broad categories of control.

Prevention

The State may act to prevent an infringement of the specified laws.

Punishment

The State may act to punish an infringement committed within its territory or territorial sea.

This distinction is important for examinations.

Memory Rule

Contiguous Zone = Prevent + Punish

But only in relation to the four specified categories.

Contiguous Zone Is Not Full Jurisdiction

The coastal State does not possess unlimited jurisdiction in the contiguous zone.

Its powers must remain connected with:

• customs;
• fiscal;
• immigration;
• sanitary matters.

Therefore, the contiguous zone should not be confused with the territorial sea.

Contiguous Zone and Territorial Sovereignty

The territorial sea forms part of the maritime territory over which the coastal State exercises sovereignty.

The contiguous zone does not.

The coastal State’s authority in the contiguous zone is therefore:

Limited

Purpose-specific

Enforcement-oriented

Contiguous Zone and EEZ

The contiguous zone and EEZ can overlap geographically.

The EEZ extends up to 200 nautical miles from the baseline.

Therefore, the contiguous zone is generally located within the broader geographical area of the EEZ.

However, the legal rights are different.

Contiguous Zone

Limited enforcement control over:

• customs;
• fiscal;
• immigration;
• sanitary matters.

EEZ

Coastal State has:

• sovereign rights over natural resources;
• jurisdiction over specified activities;
• other rights and duties under UNCLOS.

Contiguous Zone vs Territorial Sea vs EEZ

Feature	Territorial Sea	Contiguous Zone	EEZ
Maximum extent	12 nm	24 nm	200 nm
Measured from	Baseline	Baseline	Baseline
Legal character	Sovereignty	Limited control	Sovereign rights + specified jurisdiction
Main provision	Articles 2–32	Article 33	Articles 55–75
Foreign navigation	Innocent passage	Navigation freedoms subject to applicable law	Navigation freedoms
Customs	Broad coastal-State authority	Prevention/punishment	No general EEZ customs zone
Immigration	Coastal-State jurisdiction	Prevention/punishment	No general EEZ immigration jurisdiction
Fisheries	Coastal-State sovereignty	Not the basis of fisheries jurisdiction	Resource rights
Natural resources	Sovereignty	Not the principal purpose	Sovereign rights

Contiguous Zone and Freedom of Navigation

Foreign ships retain navigation rights in the contiguous zone.

The coastal State cannot generally prohibit navigation merely because a vessel is within the contiguous zone.

Its authority is limited to the purposes recognised by international law.

Thus:

Contiguous Zone

≠

Second Territorial Sea

This is a very important examination point.

No General Sovereignty

A coastal State cannot claim that the contiguous zone is part of its territory simply because it has enforcement powers there.

The zone is an area of limited functional jurisdiction.

Relation to Territorial Sea

The contiguous zone begins beyond the territorial sea.

Therefore:

Territorial Sea ends at 12 nm

Contiguous Zone may continue to 24 nm

The same baseline is used for calculating both limits.

Customs Enforcement Example

Suppose a vessel is suspected of carrying illegally imported goods toward a coastal State.

If the vessel is within the contiguous zone, the coastal State may take appropriate measures under Article 33 to prevent infringement of its customs laws.

The purpose is to protect the State’s customs regime rather than to exercise unlimited territorial jurisdiction.

Immigration Example

Suppose a vessel is approaching the coast carrying persons who intend to enter the State unlawfully.

The coastal State may exercise the control permitted by Article 33 to prevent infringement of its immigration laws.

Again, this does not turn the entire contiguous zone into territorial waters.

Sanitary Example

A vessel approaching the coast may present a public-health concern.

The coastal State can exercise relevant control under Article 33 concerning its sanitary laws.

This is particularly important in relation to:

• quarantine;
• communicable diseases;
• public-health protection.

Fiscal Example

Where conduct outside the territorial sea threatens to infringe fiscal laws applicable within the State or territorial sea, the coastal State may exercise the Article 33 control necessary to prevent or punish the relevant infringement.

Contiguous Zone and Smuggling

The contiguous zone is particularly significant in combating:

• customs violations;
• smuggling;
• illegal immigration;
• public-health violations.

It provides a legal buffer beyond the territorial sea.

Enforcement Jurisdiction

The contiguous zone is therefore often described as an enforcement zone.

The coastal State is given limited powers beyond its territorial sea so that violations affecting its territory or territorial sea can be addressed before or after they occur, within the scope of Article 33.

The “Prevent and Punish” Principle

Remember:

Prevention

Prevent infringement

↓

Punishment

Punish infringement

↓

Four Laws

Customs + Fiscal + Immigration + Sanitary

This is the core of Article 33.

Contiguous Zone and Hot Pursuit

The contiguous zone should also be understood alongside the doctrine of hot pursuit under Article 111 UNCLOS.

Hot pursuit concerns pursuit of a foreign ship that has violated the laws and regulations of the coastal State.

It may begin when the coastal State has good reason to believe that the ship has violated applicable laws.

The conditions and continuation of hot pursuit are governed separately by Article 111.

Therefore:

Contiguous Zone ≠ Hot Pursuit

They are related maritime enforcement concepts but have different legal bases.

Contiguous Zone and Piracy

Piracy is primarily governed by Articles 100–107 UNCLOS and concerns acts on the high seas or in places outside the jurisdiction of any State.

The contiguous zone should not be treated as a special piracy jurisdiction.

However, maritime enforcement operations may involve overlapping legal regimes depending on where conduct occurs.

Contiguous Zone and Fisheries

Article 33 itself does not create a general fisheries jurisdiction for the contiguous zone.

Fisheries jurisdiction is principally associated with the coastal State’s rights in its:

Territorial Sea

and

EEZ

This is an important distinction.

Contiguous Zone and Natural Resources

The contiguous zone does not give the coastal State a general right to exploit natural resources simply because an area lies within 24 nautical miles.

Resource rights must be determined under the applicable maritime-zone regime, particularly the territorial sea and EEZ.

Contiguous Zone and Marine Scientific Research

Article 33 does not establish a general power to regulate all marine scientific research in the contiguous zone.

Other UNCLOS provisions determine the applicable legal regime.

Contiguous Zone and Environmental Protection

The contiguous zone itself does not create general territorial sovereignty over environmental matters.

Environmental jurisdiction must be based on the relevant UNCLOS provisions and other applicable international law.

Contiguous Zone and International Law

The coastal State’s enforcement powers must comply with:

• UNCLOS;
• customary international law;
• applicable treaties;
• principles governing maritime navigation.

The existence of an enforcement power does not permit arbitrary action against foreign ships.

Delimitation of Contiguous Zones

Where the coasts of two States are opposite or adjacent, their potential contiguous zones may overlap.

Because the contiguous zone cannot extend beyond 24 nautical miles from the baseline, delimitation becomes necessary where the geographical distance between States is insufficient to allow each to claim a full zone.

UNCLOS does not provide a detailed standalone contiguous-zone delimitation article equivalent to Article 15 for territorial seas.

In practice, applicable rules of international law and agreement between States become important.

Contiguous Zone and Islands

An island that generates maritime zones under UNCLOS can generally have:

• territorial sea;
• contiguous zone;
• EEZ;
• continental shelf,

subject to the specific rules applicable to islands.

However, Article 121(3) provides that rocks which cannot sustain human habitation or economic life of their own have no EEZ or continental shelf.

They can nevertheless have a territorial sea and, consequently, a contiguous zone.

Artificial Islands

Artificial islands do not have their own territorial sea and therefore do not independently generate a contiguous zone.

This follows from the UNCLOS regime governing artificial islands and maritime zones.

Contiguous Zone and Archipelagic States

Archipelagic States have special rules under Part IV UNCLOS.

Their maritime zones must be understood in conjunction with the archipelagic baseline regime.

The contiguous zone may be measured from the relevant baselines in accordance with UNCLOS.

Contiguous Zone and Landlocked States

The contiguous zone is a maritime entitlement of coastal States.

Landlocked States do not possess a contiguous zone because they have no coastline from which such maritime zones can be measured.

Historical Development

The idea of a zone adjacent to the territorial sea for limited enforcement purposes developed before UNCLOS through State practice.

The modern treaty framework codified this concept in Article 33 UNCLOS.

The contiguous zone therefore represents a compromise between:

Strict territorial sovereignty

and

Complete freedom of navigation beyond the territorial sea.

Important UNCLOS Articles

Article 2

Legal status of the territorial sea

Article 3

Breadth of territorial sea – 12 nautical miles

Article 5

Normal baseline

Article 7

Straight baselines

Article 8

Internal waters

Article 15

Territorial-sea delimitation

Article 17

Innocent passage

Article 33

Contiguous zone

Article 55

EEZ

Article 57

EEZ breadth – 200 nautical miles

Article 111

Right of hot pursuit

Article 33 – Exam-Focused Breakdown

Article 33(1)

Coastal State may exercise necessary control to:

Prevent

or

Punish

infringement of:

Customs

Fiscal

Immigration

Sanitary

laws.

Article 33(2)

Contiguous zone may extend to:

24 nautical miles from the baseline

Article 33 Memory Formula

12 + 12 = 24

12 nm

→ Territorial Sea

Next 12 nm

→ Contiguous Zone

Total from baseline

→ 24 nm

Four-Law Memory Trick

CFIS

C → Customs

F → Fiscal

I → Immigration

S → Sanitary

Therefore:

Article 33 = 24 nm + CFIS + Prevent/Punish

Territorial Sea → Contiguous Zone → EEZ

Baseline

↓

0–12 nm

Territorial Sea

↓

12–24 nm

Contiguous Zone

↓

24–200 nm

EEZ

This is one of the easiest diagrams to reproduce in an examination.

Important Case Law

Unlike the territorial sea and maritime delimitation, there is relatively little major ICJ case law focused exclusively on Article 33.

Nevertheless, broader maritime-jurisdiction cases are useful for understanding the relationship between coastal-State authority and maritime zones.

Fisheries Case (United Kingdom v Norway)

The Anglo-Norwegian Fisheries Case (1951) is primarily important for baselines and coastal geography rather than Article 33 itself.

It is relevant because the extent of maritime zones, including a contiguous zone, depends upon the legally established baseline.

S.S. Lotus

The S.S. Lotus (France v Turkey) case concerned jurisdiction following a collision on the high seas.

It is not a direct Article 33 case, but it remains useful when studying the broader question of jurisdiction over maritime spaces.

Nicaragua v Colombia

The ICJ’s maritime delimitation jurisprudence in Nicaragua v Colombia is useful for understanding the interaction between maritime entitlements, coastal geography and delimitation.

It should not, however, be presented as a leading case specifically interpreting Article 33.

Contiguous Zone – Jurisdictional Character

The key conceptual distinction is:

Territorial Sea

Territorial Jurisdiction

Contiguous Zone

Limited Enforcement Jurisdiction

EEZ

Functional/Sectoral Jurisdiction and Sovereign Rights

High Seas

Flag-State Jurisdiction + Limited Exceptions

Common Examination Confusions

Confusion 1: Contiguous Zone = Territorial Sea

Incorrect.

The contiguous zone is not subject to full coastal-State sovereignty.

Confusion 2: Contiguous Zone Extends 24 nm Beyond Territorial Sea

Incorrect.

It extends to a maximum of 24 nm from the baseline.

Thus, where fully claimed:

12 nm territorial sea + 12 nm contiguous zone = 24 nm from baseline.

Confusion 3: Contiguous Zone Gives General Fisheries Jurisdiction

Incorrect.

Article 33 is limited to the four specified categories.

Confusion 4: Contiguous Zone Gives Full Criminal Jurisdiction

Incorrect.

The powers under Article 33 are limited and connected to the specified laws.

Confusion 5: Contiguous Zone Is Part of State Territory

Incorrect.

The coastal State has limited control, not full territorial sovereignty.

Confusion 6: Every Coastal State Automatically Has a 24 nm Zone

The legal entitlement exists under UNCLOS, but its actual maritime claim must be established consistently with the Convention and applicable national law.

Quick Revision

• Contiguous zone → Article 33 UNCLOS.
• It lies beyond the territorial sea.
• Maximum extent → 24 nautical miles from the baseline.
• Territorial sea → up to 12 nautical miles.
• The contiguous zone therefore normally occupies the area between 12 and 24 nautical miles from the baseline.
• It is not part of the coastal State’s territory in the same sense as the territorial sea.
• Coastal State exercises limited control, not full sovereignty.
• The control is for:
  • customs;
  • fiscal;
  • immigration;
  • sanitary laws.
• Coastal State may act to:
  • prevent infringement;
  • punish infringement.
• The laws concerned must relate to the State’s territory or territorial sea.
• Article 33 does not provide general jurisdiction over:
  • fisheries;
  • natural resources;
  • all criminal offences;
  • all environmental matters.
• Foreign ships retain navigation rights.
• Contiguous zone is not a second territorial sea.
• EEZ can extend to 200 nautical miles.
• Contiguous zone can geographically fall within the EEZ.
• Article 111 separately governs hot pursuit.
• Landlocked States do not have contiguous zones.
• Artificial islands do not independently generate maritime zones.
• Islands can generate a contiguous zone where they generate a territorial sea.
• Article 33(2) → 24 nm from baseline.
• Memory formula → Article 33 = 24 nm + CFIS + Prevent/Punish.
• Important related cases:
  • Anglo-Norwegian Fisheries;
  • S.S. Lotus;
  • Nicaragua v Colombia.

One-Line Memory Trick

Contiguous Zone

“24 – CFIS – Prevent & Punish”

24 → 24 nautical miles from baseline

C → Customs

F → Fiscal

I → Immigration

S → Sanitary

Prevent + Punish

Maritime-Zone Memory

Internal Waters → Sovereignty

Territorial Sea → 12 nm + Sovereignty + Innocent Passage

Contiguous Zone → 24 nm + CFIS Control

EEZ → 200 nm + Resource Rights

High Seas → Freedom

Conclusion

The contiguous zone is a maritime zone adjacent to the territorial sea in which a coastal State enjoys limited enforcement powers under Article 33 of UNCLOS.

Its maximum extent is 24 nautical miles from the baseline, meaning that where the full entitlement is claimed, it covers the area immediately beyond the 12-nautical-mile territorial sea.

The central feature of the contiguous zone is that it does not confer full sovereignty upon the coastal State. Instead, it permits the State to exercise the control necessary to prevent or punish infringement of customs, fiscal, immigration and sanitary laws applicable within its territory or territorial sea.

This makes the contiguous zone an enforcement belt, rather than an extension of territorial waters.

The most important distinction is therefore:

Territorial Sea → Sovereignty

Contiguous Zone → Limited Enforcement Control

EEZ → Sovereign Rights over specified resources and jurisdiction

For examination purposes, the entire concept can be remembered through one formula:

Article 33 = 24 nm + CFIS + Prevent & Punish

Where:

24 nm = maximum distance from baseline

CFIS = Customs, Fiscal, Immigration, Sanitary

Prevent & Punish = purpose of coastal-State control