Innocent Passage

Innocent passage is the right of ships of all states to pass continuously and expeditiously through another state’s territorial sea, provided the passage is not prejudicial to the coastal state’s peace, good order, or security. UNCLOS Articles 17 to 32 codify it: Article 19 lists the activities that render passage non-innocent (any threat or use of force, weapons exercises, intelligence collection, fishing), and Article 21 limits the laws the coastal state may apply. Submarines must navigate on the surface and show their flag.