"A recent incident in the Arabian Sea and the Strait of Hormuz has raised questions regarding the legal framework surrounding the rights of transit and innocent passage in the territorial seas of coastal nations. Specifically, the rights of vessels to utilize the regime of transit passage through straits used for international navigation unimpeded appear to have been challenged. Iran, the coastal nation whose territorial waters include the Strait of Hormuz, recently detained the Marshall Islands-flagged M/V Maersk Tigris while transiting the Strait. The United Nations Convention on the Law of the Sea (UNCLOS) established a legal order for peaceful uses of the seas and oceans. Included in the UNCLOS (Part II, Sections 2 and 3) is a legal framework establishing the limits of the territorial seas of coastal nations, as well as the right of innocent passage through these waters. The territorial seas, water over which the coastal nation enjoys sovereignty, extend 12 nautical miles from the coastline. However, vessels enjoy the right of innocent passage, continuous and expeditious passage that is not prejudicial to the peace, good order, or security of the coastal nation, through these waters."
CRS Legal Sidebar, May 18, 2015