Owing to soaring energy needs and improved drilling technology, offshore hydrocarbon activities have been on the rise in recent years. A delimited maritime boundary is an essential precondition for the establishment of a safe and stable environment which will facilitate investment and development. Nevertheless, the conclusion of delimitation agreements can be a difficult task due to competing interests and long-standing enmities among neighbouring countries. Significant maritime areas remain undelimited. In order to avoid the problems of both unilateral activities and a complete ‘moratorium’ in undelimited areas, Articles 74(3) and 83(3) of the 1982 United Nations Convention on the Law of the Sea impose two obligations of conduct: pending delimitation agreement, States are under duty to ‘make every effort to enter into provisional arrangements of a practical nature’, while, at the same time, the interested parties should refrain from acts that might ‘jeopardize or hamper the reaching of the final agreement’. Bearing this in mind, it is argued that unilateral drilling and, under certain circumstances, unilateral seismic surveys in undelimited maritime areas should not be allowed and such conduct might trigger State responsibility. However, given that complete inactivity in such areas was not the intention of the drafters of the Convention, it is argued that several activities may be permitted as long as they are performed in good faith and do not put any final agreement at risk.

Recent international jurisprudence has shown considerable uncertainty with regard to the delimitation of the territorial sea. While international tribunals endorse a two-stage approach to territorial sea delimitation, there is a lack of judicial consensus on the practical implementation of such an approach. This article argues that the rule-exception relationship between equidistance and special circumstances, as reflected in the drafting history of LOSC Article 15 and in jurisprudence prior to 2007, should inform the delimitation of the territorial sea. Cases since 2007 which have strayed from the earlier jurisprudence on LOSC Article 15, should be seen as a misconstruction of the law applicable to territorial sea delimitation.