A coastal state is a term found in the law of the sea. Although widely used in the legal documents, including the UN Convention on the Law of the Sea (UNCLOS), this term lacks a precise definition. The "essential idea" of a coastal state is having an open sea coast and asserting the sovereignty or jurisdiction in the areas of the sea adjacent to this coast. Norway, Canada, and Chile are examples of the coastal states, Churchill counts up a total of 150 of such states.