The ‘SoU’ must go on: Redefining the scope of the Bengal rule as an alternative to Article 76 of UNCLOS

The Statement of Understanding (SoU) emerged as an alternative method for delineating the outer limits of the continental shelf. To prevent inequities for States whose sediment accumulation extends hundreds of kilometers seaward but whose foot of slope lies unusually close to their baselines, Sri Lanka championed this initiative. Although originally intended for the Bay of Bengal, the mechanism has since been invoked by other States that consider themselves to meet the relevant geological criteria. In this context, Myanmar, Sri Lanka, Kenya, and Spain (in relation to the Galicia region) have all relied on the SoU. The central issue, however, lies in its interpretation. The SoU is set out in only five paragraphs contained in Annex II of the Final Act of UNCLOS, providing States with a degree of discretion. Nevertheless, the Commission on the Limits of the Continental Shelf (CLCS) applies its own interpretative approach. This paper offers a legal and technical examination of the conditions required for applying the SoU method. It analyzes the legal framework governing its use, highlighting the challenges that arise in practice. A central focus is the interpretative role of the CLCS. Given the absence of clear standards and the intricacies of individual submissions, this study critically evaluates how the CLCS has addressed the uncertainties surrounding the SoU method. The analysis is grounded in a detailed review of State submissions and the practice of the CLCS, offering insights into the Commission’s evolving interpretative approach and the implications for coastal States seeking to extend their continental shelf. • The SoU is an alternative for States with specific geological characteristics. • Four States have invoked the SoU in support of their extension submissions. • The SoU requirements are being interpreted by the CLCS, a technical body. • The uncertainties that arise are sometimes of a legal nature.