UNCLOS articles 74 and 83 require that equitable solutions are achieved on the basis of international law. This entails an obligation to consider all relevant circumstances. Courts and tribunals traditionally delimit bilateral boundaries by delimiting an equidistance line and only adjust it by reference to relevant circumstances. Such circumstances primarily relate to coastal geography and the time of delimitation. However, judicial decisions can consider coastal instability, and complicated scientific evidence. This has allowed courts and tribunals to assess seasonal changes to ice sheets and access to fish stocks; the status of coastal features; and feasibility of potential base points. Indeed, foreseeable changes to coastal geography can affect the delimitation process to produce boundaries that are less dependent on particularly unstable coastal features. This can strengthen the link between fluctuating maritime limits and permanent boundaries and prevent invocation of the rebus sic stantibus principle. Foreseeable changes to coastal geography can affect the choice of base points or delimitation methods and lead to an adjustment of provisional boundaries.

This chapter introduces the conceptual framework of delimitation methodology. It reviews the sources of the law of maritime delimitation applicable to the delimitation of the continental shelf beyond 200 nm. More specifically, it examines the elements of delimitation methodology and the formulations of delimitation methodology that evolve over time. On that basis, this chapter raises the methodological questions to be addressed in the delimitation of the continental shelf beyond 200 nm and develops the approach for their analysis, which goes beyond the prevailing three-stage approach established in the jurisprudence since the 2009 Black Sea case.

This chapter examines the role of private rights in the process of land and maritime delimitation. To determine this, the study performs a comparative analysis in pairs. Firstly, it compares the effect of private rights in land and maritime delimitation treaties. Then it compares the effect of private rights in land and maritime delimitation rulings. A synthesis of the findings reached shows that the effect of private rights is extensive and significant in land delimitation, but restricted or even absent in maritime delimitation. Hence, the risk of reallocation is greater for offshore private rights in the first place. This asymmetry has important implications for private actors operating in contested waters and for international law in general.