Historic waters in the law of the sea is a concept designating the waters that are treated by a coastal state as a part of its internal waters, contrary to the established international law, but with acquiescence of other states. Historic bay is a narrower term for a bay with such a "historic title".[1] The concept of historic waters appeared at the end of the 19th century and some commentators consider it to be anachronistic in the 21st century.[2] Ancient title is a similar judicial doctrine based on a different reasoning: during the Age of Discovery and prior to the 18th-century concept of freedom of the high seas, the open sea was considered territoria nullius (nobody's territory) and thus claims for newly discovered parts of it by colonial powers were legitimate.[3] Some historic bay claims were subsequently converted to juridical bays (for example, Delaware Bay and Chesapeake Bay in the US). The goal of protecting "vital" waters is pursued by the states through the modern maritime zones.[2]