Ocean energy is a term used to describe renewable energy derived from the sea, including ocean wave energy, tidal and open-ocean current energy (sometimes called marine hydrokinetic energy), tidal barrages, offshore wind energy, and ocean thermal and salinity gradient energy. Shallow water offshore wind is a commercial technology (over 1,500 MW capacity installed in Europe). The technologies to convert the other ocean energy resources to electricity, including deepwater offshore wind technology, albeit in their infancies, exist. These technologies are ready for full-scale prototype and early commercialization testing at sea. This paper highlights the technology development status of various energy conversion technologies.