Under UNCLOSIII
They would have been in territorial waters, and subject to
the following section
Territorial waters Out to 12 nautical miles from the baseline, the coastal state is free to set laws, regulate use, and use any resource. Vessels were given the right of "
innocent passage" through any territorial waters, with strategic straits allowing the passage of military craft as "transit passage", in that naval vessels are allowed to maintain postures that would be illegal in territorial waters. "Innocent passage" is defined by the convention as passing through waters in an expeditious and continuous manner,
which is not “prejudicial to the peace, good order or the security” of the coastal state. Fishing, polluting, weapons practice, and spying are not “innocent", and submarines and other underwater vehicles are required to navigate on the surface and to show their flag. Nations can also temporarily suspend innocent passage in specific areas of their territorial seas, if doing so is essential for the protection of its security.