National authorities have the power to allow private activities in areas under the jurisdiction of the coastal state, the International Seabed Authority can license activities in the area, but in international waters, private activities have much fewer controls. Common property regimes are even scarcer than on land given the mobile nature of many marine resources, which makes the exclusion of non-authorised users extremely difficult. Our sparse presence in the sea also makes it much more difficult, and costly, to exercise adequate law enforcement.