The flag state of a merchant vessel is the
jurisdiction Jurisdiction (from Latin 'law' + 'declaration') is the legal term for the legal authority granted to a legal entity to enact justice. In federations like the United States, areas of jurisdiction apply to local, state, and federal levels. Jur ...
under whose laws the vessel is registered or licensed, and is deemed the nationality of the vessel. A merchant vessel must be registered and can only be registered in one jurisdiction, but may change the register in which it is registered. The flag state has the authority and responsibility to enforce regulations over
vessels Vessel(s) or The Vessel may refer to: Biology *Blood vessel, a part of the circulatory system and function to transport blood throughout the body *Lymphatic vessel, a thin walled, valved structure that carries lymph *Vessel element, a narrow wat ...
registered under its flag, including those relating to inspection, certification, and issuance of
safety Safety is the state of being "safe", the condition of being protected from harm or other danger. Safety can also refer to the control of recognized hazards in order to achieve an acceptable level of risk. Meanings There are two slightly dif ...
pollution Pollution is the introduction of contaminants into the natural environment that cause adverse change. Pollution can take the form of any substance (solid, liquid, or gas) or energy (such as radioactivity, heat, sound, or light). Pollutants, the ...
prevention documents. As a ship operates under the laws of its flag state, these laws are applicable if the ship is involved in an admiralty case. The term " flag of convenience" describes the business practice of registering a
merchant ship A merchant ship, merchant vessel, trading vessel, or merchantman is a watercraft that transports cargo or carries passengers for hire. This is in contrast to pleasure craft, which are used for personal recreation, and naval ships, which are ...
in a state other than that of the ship's owners, and flying that state's
civil ensign A civil ensign is an ensign (maritime flag) used by civilian vessels to denote their nationality. It can be the same or different from the state ensign and the naval ensign (or war ensign). It is also known as the merchant ensign or merchant flag. ...
on the ship. Ships may be registered under flags of convenience to reduce operating costs, or else to avoid the regulations of, or inspection and scrutiny by, the country of the original owner. Normally the nationality (i.e., flag) of the ship determines the taxing jurisdiction. Since the Flag Right Declaration of 1921, it has been recognised that all states—including land-locked countries—have a right to maintain a ship register and be a ship's flag state. Because of the failure of some flag states to comply with their survey and certification responsibilities, especially flag-of-convenience states that have delegated their task to classification societies, a number of states have since 1982 established port state controls of foreign-registered ships entering their jurisdiction. As at January 2010, Panama was the world's largest flag state, with almost a quarter of the world's ocean-going tonnage registered there. The United States and the United Kingdom had only about 1% each.


Until World War II nations were able to maintain their dominance, or in some cases, even improve their position in maritime trade by offering vessels exclusive protection for flying their flags, which would in turn give the nation exclusive control over the vessels. Shipowners during this time needed protection from pirates and privateers which was provided by naval vessels of the flag state. In some cases states offered subsidies to the shipbuilding industries. In addition to these incentives, states might impose restrictions based on flag state, closing ports to other ships. One well known example of how this was applied is the case of England, which restricted the import of Asian goods only to American and British vessels. England only opened its ports after it had maneuvered itself into a position of strength, and then most like only to gain access to other continental ports. Similarly, France imposed a trade monopoly on its colonies which remained in place until 1869.

Ship register

Ships must be registered in the ship register of the jurisdiction whose flag it is flying. Flag registers in many countries are open to ships with foreign owners. Normally, each flag state has only one ship register, but several countries have more than one register: *Denmark, France and Norway maintain an international register to compete with flags of convenience. *The
Kingdom of the Netherlands , national_anthem = ) , image_map = Kingdom of the Netherlands (orthographic projection).svg , map_width = 250px , image_map2 = File:KonDerNed-10-10-10.png , map_caption2 = Map of the four constituent countries shown to scale , capital = ...
allows the different constituent countries to set up their own registers under the Dutch flag. *Several territories over which the British Crown holds sovereignty have their own register. Most notably, the Isle of Man has a significant register. *Hong Kong, the special administrative region of China, has a separate ship register, the fourth largest in the world, in addition to China's own ship registry.

Flag state enforcement

Flag states must, in accordance with the United Nations Convention on the Law Of the Sea (
UNCLOS The United Nations Convention on the Law of the Sea (UNCLOS), also called the Law of the Sea Convention or the Law of the Sea Treaty, is an international agreement that establishes a legal framework for all marine and maritime activities. , 167 c ...
) ensure that ships under their flag comply with international regulations, often adopted by the UN's International Maritime Organization ( IMO), on matters of safety, navigation, crewing etc. Part XII entail special provisions on protecting the marine environment, which includes placing special obligations on flag states to ensure compliance with international environmental legislation such as
MARPOL The International Convention for the Prevention of Pollution from Ships, 1973 as modified by the Protocol of 1978, or "MARPOL 73/78" is one of the most important international marine environmental conventions. MARPOL 73/78, MARPOL is an amalg ...
. Failure to do so, can result in the flag state losing its jurisdiction over ships under its flag, also when these commit violations on the high seas.

Flag state control

Each flag state has set up its own flag state control system: * In Australia, the Australian Maritime Safety Authority (AMSA) provides flag state control. * In Canada,
Transport Canada Transport Canada (french: Transports Canada) is the department within the Government of Canada responsible for developing regulations, policies and services of road, rail, marine and air transportation in Canada. It is part of the Transporta ...
is responsible for flag state control under the ''Canada Shipping Act, 2001''. *In France, the Ships Safety Centers are in charge of Flag state control. * In Hong Kong, the Marine Department is responsible for flag state control and enforcement under the Flag State Quality Control Scheme. * In India, the Directorate General of Shipping is responsible for life, health, vessel and the environment for Indian registered ships and ships at Indian ports. * In the United Kingdom, the Maritime and Coastguard Agency (MCA) is responsible for flag state control. * In the United States, the Coast Guard, under the authority of various federal laws, regulations and international conventions and treaties, the Officer in Charge Marine Inspections is responsible for the inspection of US flag vessels to ensure compliance operating throughout the world. * In
Vanuatu Vanuatu ( or ; ), officially the Republic of Vanuatu (french: link=no, République de Vanuatu; bi, Ripablik blong Vanuatu), is an island country located in the South Pacific Ocean. The archipelago, which is of volcanic origin, is east of no ...
, the Vanuatu Maritime Authority has the responsibility to enforce maritime laws and exercise flag state control.

See also

* Port state control




* Mansell, J.N.K. (2009): ''Flag State Responsibility: Historical Development and Contemporary Issues'', Springer. * Jesper Jarl Fanø (2019). ''Enforcing International Maritime Legislation on Air Pollution through UNCLOS''. Hart Publishing. Ship registration he:דגל (ספנות)