The flag state of a merchant vessel is the jurisdiction under whose laws the vessel is registered or licensed, and is deemed the nationality of the vessel.

What does it mean to flag a vessel?

Definition: Each vessel normally flies the flag of the owner's country. That means it is registered in the national register of that particular country. ... Generally flagging out refers to the practice of switching the vessel's registration to another country to fly operate it under a "flag of convenience".

Why do vessels have flags?

Under international law, every merchant ship must be registered with a country, known as its flag state. That country has jurisdiction over the vessel and is responsible for inspecting that it is safe to sail and to check on the crew's working conditions.