Superposition of national legal regimes in maritime disputed areas is governed by a set of international rules provided for in Articles 74 and 83 of the United Nations Convention on the Law of the Sea (UNCLOS). According to those articles, and as the international jurisprudence confirmed, not all activities are permissible in those areas, and claimant States are bound by a general obligation of restraint that, at the very least, imposes a duty not to permanently harm the marine environment. States are also required to negotiate in good faith provisional arrangements of a practical nature aiming to limit conflicting national legislation and conflicting activities. In the absence of provisional arrangements, the legality of States’ activities in an area of overlapping maritime claims is not clear. This paper reviews in the light of the international jurisprudence and State practice the regime devoted to disputed maritime areas. It then highlights the main features of the obligation of self-restraint in a context where each State is trying to assert its sovereignty and maximise the benefits of its claim over a maritime disputed area.