It is now clear that a dispute concerning sovereignty over land territory does not fall within the scope of a dispute concerning the interpretation or application of the United Nations Convention on the Law of the Sea (LOSC), unless the external issue arose as an incidental question in the application of the Convention. Less clear, however, is under what circumstances the competence of LOSC tribunals extend to the determinations of law that are ancillary/incidental to the main issue regarding a dispute concerning the interpretation or application of the Convention. This article brings together recent developments in LOSC jurisprudence regarding the issue of mixed disputes and points to some of the current uncertainties.