The development of offshore renewable energy capacity is a key transition mechanism for the EU. Large commercial floating wind energy projects are being announced in some member states and novel ocean energy technology is reaching a level of maturity that will see it deployed in the near future. Recent innovations that can further accelerate a marine energy transition include the deployment of floating wind and floating solar farms, increased efficiency in wave and tidal devices, and the development of energy islands. However, achieving the required offshore wind and energy installed capacity by 2050 will require a major step-change for the sector. It means multiplying the capacity for offshore renewable energy by nearly 30 times by 2050. It will also require a major electrification of ships and ports and will entail a greater use of green hydrogen in the sector. At the same time, accelerating energy development while keeping its footprint and impact to a minimum will be challenging and entail a high degree of coordinated governance.