Atmospheric emissions from the maritime sector far exceed those of the road transport sector.
Fortunately ships can be fuelled directly with hydrogen, or alternatively it can be used as a feedstock for producing green liquid fuels. Short-range hydrogen boats and ferries are currently being demonstrated, while multi-MW fuel cells and large scale hydrogen production facilities are being developed to facilitate zero-emission ocean going ships.
Because of packaging constraints on board ships, it is likely that some types will be fuelled by hydrogen while others will be fuelled by a liquid fuel synthesised from green hydrogen (e.g. synthetic natural gas, diesel, ammonia).