An equidistance/equiratio method of maritime delimitation on the Earth ellipsoid

Abstract

The United Nations Convention on the Law of the Sea provides only basic legal principles for maritime delimitation disputes among coastal states. The implementation of maritime delimitation requires the comprehensive use of legal, political, and technical means by relevant states to generate the expected equitable results. Accurate calculation of the maritime delimitation boundary provides the basis for this equitable delimitation. Although the final determination of the maritime boundary is the result of diplomatic agreement, both disputing parties need a reasonable starting line as the point of departure for negotiations. As such, the equidistance/equiratio line can aid in this important task. The traditional three-point methods have many disadvantages, however, including a complex calculation process, dependence on map projections, and difficulty in calculating the equiratio line. Although the elastic method, water-line method, and mesh-points method can be used to calculate the equidistance/equiratio line, the boundary pattern is complex and the number of turning points is large. As a result, a great deal of adjustment and simplification is required, and simplifying the boundary line requires a complex diplomatic negotiation process. To solve these problems, we proposed a new three-point equidistance/equiratio method based on the Earth ellipsoid, which is called pendulum method. By choosing different geographical scenarios, we used the new method and CARIS to calculate the boundary and compared the demarcation results. The results demonstrated that the proposed method could generate an equidistance/equiratio line in various scenes using a unified algorithm. The algorithm was simple and efficient and was not limited by the map projection.