Where does international airspace begin in relation to a nation's coastline?

International airspace typically begins at a point that is 12 nautical miles from a nation's coastline. This demarcation aligns with the territorial waters recognized under the United Nations Convention on the Law of the Sea, which grants countries sovereignty over these waters. As such, within the 12 nautical miles, a nation has rights to control its airspace in the same way it governs its territorial waters.

Beyond this 12 nautical mile limit, airspace is considered international, allowing for free navigation by international aircraft. This regulation is crucial for the fluidity of international aviation and is recognized globally, making it essential for pilots to understand where national jurisdiction ends and international airspace begins. This understanding helps in flight planning and compliance with various international air traffic management regulations.