This paper attempts to predict changes and trends in future UK marine resource development and management. It does this by asserting that our presumptions about marine resources and the way in which they should be used are changing. Some emerging presumptions may not only preclude the use of existing technologies in some cases (e.g. dumping at sea), but may also act as drivers to the development of new technologies, such as offshore wave and wind power generation devices. A variety of maritime industries exploiting both living and non-living resources are examined individually. Attention is paid to marine conservation and the technologies that are important to providing generally for the protection of the marine environment. The authors conclude that major drivers will be ones for cleaner seas, for the development of renewable marine energy sources, and for the innovative management of the consequences of sea-level rise. With regard to the exploitation of living resources the finite limits to fisheries are stressed, and the present importance of industrial fishmeal supplies for salmon farming are highlighted. One of the greatest potential technological advances is predicted to be in marine habitat mapping. Given the changes in presumptions about our use of the seas, one over-riding conclusion is that the sustainable development of marine resources, and the conservation of priority habitats and species (for both the local seas and global oceans), must involve sustainable mechanisms for conflict resolution and decision-making.