This article examines reactions to the South China Sea and Chagos Marine Protection Area arbitrations under the United Nations Convention on the Law of the Sea (UNCLOS), in particular concerns about the potential widening of Part XV jurisdiction and its impact on the dispute resolution system's consent basis. It argues that assessing the impact of such cases involves a characterization of both the function of Part XV and of international judges. Ultimately, it suggests that the best test of whether UNCLOS case law has gone too far is the reaction of States in designing dispute settlement under the new Agreement under UNCLOS on the Conservation and Sustainable Use of Marine Biological Diversity of Areas Beyond National Jurisdiction.