The article discusses different ways to generate renewable energy from the oceans, such as using waves, tides, currents, and temperature and salinity differences. It also explores the potential of offshore wind and floating solar energy. These technologies could provide a significant amount of clean electricity, especially for coastal and island communities. The book gathers insights from experts in academia and industry to give a comprehensive overview of ocean energy technologies, their feasibility, and how they can be connected to the power grid.