Transit passage is a concept of the law of the sea, which allows a vessel or aircraft the freedom of navigation or overflight solely for the purpose of continuous and expeditious transit of a strait between one part of the high seas or exclusive economic zone and another.
[1] Within such straits (article 37 of UNCLOS), including Arctic straits, all ships and aircraft enjoy the right of transit passage (article 38 of UNCLOS), in accordance with Part III of UNCLOS, which means the right of navigation and overflight solely for the purpose of continuous and expeditious transit of the strait between one part of the high seas or an exclusive economic zone and another part of the high seas or an exclusive economic zone.
This navigation rule is codified in Part III of the United Nations Convention on the Law of the Sea.
[4] Transit passage exists throughout the entire strait, not just in the area overlapped by the territorial waters of the coastal nations.
[4] Innocent passage is a similar right which applies to the entire territorial sea (and certain grandfathered internal waters) of states – not just straits – and has more restrictive requirements for passing vessels.