The issue of historic rights and historic waters has long been a problematic area in the law of the sea where even basic definitions have been vague and interchangeably used in the past. The first edition of this book was entitled Historic Waters in the Law of the Sea: A Modern Re-Appraisal, and concentrated, as the title implies, on the doctrine of historic waters. The title of this expanded new edition has been broadened to take account of the important clarifications as to the doctrine of historic maritime claims generally—particularly 'historic rights' in the narrow sense which fall short of sovereignty claims. These latter rights—such as they now are—are discussed in depth in the new text. This development has come about, of course, because of the Award of the Arbitral Tribunal in Philippines v. China in 2016. This decision has, for the first time in a judicial setting, rationalised the terminology in this area of the law of the sea; and, most importantly, has clarified the close interaction of historic rights with the Law of the Sea Convention. This new edition discusses the latter issue passim, showing that much of the former customary law doctrine has now been overridden by the Convention.