The presence of third States occurs when two countries delimit their maritime boundary in a maritime area where there are more than two coastal States. The bilateral nature of maritime delimitation between two States requires the delimitation process not to prejudice the legal rights and interests of third States. On the one hand, at the procedural stage of international adjudication, third States may file an application for permission to intervene in the proceedings before a court or tribunal; at the merits stage, a third-party judicial organ may leave undecided the endpoint of a final boundary line to be delimited, so as not to affect the rights of a third State. On the other hand, in interstate maritime boundary agreements through international negotiation, in order to take care of third States' legal rights and interests, States may adopt several ways of addressing the existence of tripoints. This paper, in four parts, discusses the presence of third States in international maritime boundary delimitation. The first part gives a definition of a third State in the framework of maritime delimitation. The second part reflects on international adjudication relating to the presence of third States. The third part provides some observations on State practices relating to the existence of tripoints. The conclusion points out that there is a widening gap between maritime delimitation in theory and in practice, since recent case law particularly confines the delimitation to a purely bilateral status, without enough focus on the presence of third States, resulting in procedurally prejudicial impacts upon the legal rights and interests of third States.

中文翻译：

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国际海洋划界中第三国存在的思考

当两个国家在有两个以上沿海国的海域划定其海上边界时，就会出现第三国。两国海洋划界的双边性质要求划界过程不得损害第三国的合法权益。一方面，在国际审判的程序阶段，第三国可以申请准许介入法院或法庭的诉讼程序；在案情审理阶段，第三方司法机关可以未确定最终划定的边界线终点，以免影响第三国的权利。另一方面，在通过国​​际谈判达成的国家间海洋边界协定中，为了照顾第三国的合法权益，各国可能会采用多种方式来解决存在三点的问题。本文分四部分讨论第三国在国际海洋划界中的存在。第一部分给出了海洋划界框架下第三国的定义。第二部分反思与第三国的存在有关的国际裁决。第三部分就存在三点的国家实践提出了一些意见。结论指出，海洋划界在理论和实践上的差距越来越大，因为最近的判例法特别将划界限制为纯粹的双边地位，而没有足够重视第三国的存在，导致程序上对海洋划界产生不利影响。第三国的合法权益。