Abstract The maritime industry, responsible for 80% of all global trade and 3% of all greenhouse gas emissions, has been aiming for decarbonization for decades. With the International Maritime Organisation (IMO) aiming for net-zero carbon emissions by 2050, the implementation of the use of eco-friendly fuel and technologies has fast established itself as a priority. Hydrogen fuel cells, a new technology facing research and development, are one such alternative fuel source that has zero-carbon emissions. This paper presents a technological overview of the types of hydrogen fuel cells, the ship structural requirements for their storage and transport, the challenges associated with implementing this technology, and examples of ships currently using hydrogen fuel cells. Also provided is an in-depth analysis of hydrogen fuel cells with alternative fuels like ammonia and biofuel and with fossil fuels like heavy fuel oil (HFO) and liquified natural gas (LNG).