In maritime law, what does the term "flag state" refer to?

The term "flag state" refers specifically to the country under which a vessel is registered. This is essential in maritime law because the flag state has jurisdiction over the ship, determining its legal obligations, including safety regulations, environmental standards, and labor laws that apply to its crew. The concept is important because it means that a vessel is subject to the laws of the country whose flag it flies, allowing enforcement of those laws and responsibility for any violations.

Understanding the flag state is key in numerous contexts, such as during inspections, where authorities check compliance with the regulations mandated by the flag state. This registration provides a legal identity to the vessel, as each flag state has unique laws which govern the conduct of vessels registered under its name.