Claims of coastal states to the continental shelf and an exclusive economic zone resulted in new entitlements. They called for co-ordination. In delineating these claims, the principle of equity took on a prominent role. Equity, beyond its traditional functions in legal history, emerged in a process of trial and error as the very foundation of the principles and methodology determining the delimitation of overlapping claims to marine space. As a result, it plays in important role in the allocation of marine resources. This field of study allows for insights to be gained into the modern role and function of equity in international law, assessing both the potential and the limitations of distributive justice in the society of nations. The book undertakes a detailed analysis of the evolution and process of equity in contemporary international law of the sea. It focuses on the relationship of legal rules on delimitation, in particular equidistance, and of equitable principles and relevant factors. It explores the relationship of law and equity in complex individual cases and particular circumstances which do not lend themselves to the application of ready-made, hard and fast legal rules. The operation of maritime boundary delimitation is essentially based upon a genuine rule of equity. It is determined by a number of standards, employing in the final analysis a topical method of weighing and balancing different and competing interests in a methodologically sound manner. The study seeks to further clarify and contribute to the methodology which, in an abundant series of adjudicated and negotiated cases, has been subject to trial and error. No case is like another. Conclusions cannot be readily drawn. And yet, it is submitted that common and shared methodologies, features and consistencies can be identified and further developed. It is hoped that the book will make a contribution in conceptualizing underlying principles and the methodology which eventually may be applied to other fields of law.