International Law of the Sea

International Law of the Sea

One of the oldest and most significant branches of public international law is devoted to the international law of the sea.

This importance stems from the fact that seas have long provided nations and states with a wide range of uses, including maritime trade, navigation, and access to both living and nonliving resources.

The utilization of seas for such purposes has made it necessary to establish legal rules and regulations. As a result of this necessity, an international legal system known as the international law of the sea has emerged.

The international law of the sea consists of the set of international legal rules, regulations, and principles governing relations between states and international organizations in the context of the use of seas. The significance of this field can be clearly understood by the fact that its rules govern more than two-thirds of the Earth’s surface.

Rights and Obligations of States in Different Maritime Zones

A Brief Historical Background of the International Law of the Sea

The use of seas, like other aspects of relations among states, has always been subject to shared rules and principles governing their interactions. For this reason, seas were widely used in ancient times for various purposes. Civilizations such as the Persians, Romans, and Greeks utilized the seas for maritime trade and navigation. These uses were not exclusively peaceful, as seas were also employed for territorial expansion and military purposes.

Agreements and Conventions Related to the Law of the Sea

The United Nations Convention on the Law of the Sea, hereinafter referred to as the Convention, was signed on December 1, 1982, in Montego Bay, Jamaica, and entered into force twelve years later on November 16, 1994. An additional agreement relating to the implementation of Part XI of the Convention was adopted in July 1994 and entered into force on July 28, 1996.

This agreement and Part XI of the Convention must be interpreted and applied as a single unified instrument. To date, 135 states have become parties to the Convention and the related agreement.

International Judicial and Arbitral Practice

Given that the International Tribunal for the Law of the Sea and the International Court of Justice contribute to the formation of customary rules of maritime law through reliance on treaties related to the sea, the jurisprudence of these judicial bodies may be regarded as among the most important sources of the international law of the sea.

Internal Waters

Two legal and geographical concepts have been identified for internal waters, with the legal concept being the relevant one in this context. From a legal perspective, internal waters refer to waters located between the coastline of a state and the baseline of its territorial sea. Accordingly, wetlands connected to seas, ports, adjacent anchorages, estuaries of major rivers flowing into the sea, and coastal waters fall within the category of internal waters.

The Legal Regime of Internal Waters

International actions concerning the legal regimes of internal waters have consistently been in tension with the principles of territorial sovereignty and state exclusivity. Therefore, reference to written law and customary rules contained in instruments such as the Geneva Convention of December 9, 1923, concerning the international regime of ports, is essential. The legal regime governing internal waters has also been addressed in conventions on the law of the sea.

Maritime zones are governed by specific legal regimes that ensure order and facilitate the functional characteristics of the seas, including communication, maritime transportation, scientific research, military needs, and the regulation of peaceful uses. These zones, which are limited to maritime areas including seas and waterways, possess different legal statuses under international law. Collectively, these rules constitute the international law of the sea and international waterways.

Iran’s geographical position is such that it borders maritime areas on both its northern and southern sides. To the north lies the Caspian Sea, the largest lake in the world, while to the south are the Persian Gulf and the Sea of Oman. In addition, Iran, together with Oman, is among the states bordering the Strait of Hormuz. The Persian Gulf is a semi-enclosed sea that connects to the high seas through the Strait of Hormuz. With regard to the Caspian Sea, prior to the dissolution of the Soviet Union, its legal regime was determined by a series of agreements concluded between Iran and the Soviet Union.

Frequently Asked Questions About the International Law of the Sea