One of the main challenges of our time is to be able to guarantee energy supply at a reasonable price. Policy makers, international institutions and the private sector increasingly look to the oceans as a significant source of energy. The Law of the Sea provides the legal framework within which any maritime activity is performed and strikes a balance between the multiple activities that can take place simultaneously in the same maritime zone. This volume addresses some of the main legal challenges raised by the expansion of the ocean energy sector and its consequences for the relevant international normative and institutional framework. Some of the major themes explored include energy sources and the competition for marine space, energy security, private actors and corporate social responsibility, fragmentation or integration, evolution and reinforcement of international law and liability.