This chapter looks at the concepts of relevant coasts and relevant area. The chapter first focusses on the definition of these concepts, tracing their origins and providing an understanding of their purpose. The normative nature of the concepts of relevant coasts and relevant area is also briefly considered. Next, the different criteria that have been advanced by the case law to identify the relevant coasts and relevant area are considered. As the analysis points out, the general criteria that have been formulated by the International Court of Justice (ICJ) in Tunisia/Libya have been most often relied upon by the judiciary. The chapter then assesses how these general criteria to determine the relevant coasts and the relevant area have been applied in the circumstances of the specific case and concludes that their application raises a number of questions. In that light, the chapters considers whether there are other general criteria that are more easily applicable across the board. It is concluded that in light of the difficulties quantifiable geometric criteria run into, a preferable approach might have been to solely rely on more general precepts underlying maritime delimitation law.