The HyMethShip project reduces drastically emissions and improves the efficiency of waterborne transport at the same time. This system will be developed, validated, and demonstrated on shore with a typical engine for marine applications in the range of 2 MW (TRL 6). The HyMethShip system will achieve a reduction in CO2 of more than 97% and will practically eliminate SOx and PM emissions. NOx emissions will be reduced by more than 80%, significantly below the IMO Tier III limit. The energy efficiency of the HyMethShip system is more than 45% better than the best available technology approach (renewable methanol as fuel coupled with conventional post-combustion carbon capturing). The HyMethShip system innovatively combines a membrane reactor, a CO2 capture system, a storage system for CO2 and methanol as well as a hydrogen-fueled combustion engine into one system. The proposed solution reforms methanol to hydrogen, which is then burned in a conventional reciprocating engine that has been upgraded to burn multiple fuel types and specially optimized for hydrogen use. The HyMethShip project will undertake risk and safety assessments to ensure that the system fulfills safety requirements for on-board use. It will also take into account the rules and regulations under development for low flashpoint fuels. The cost effectiveness of the system will be assessed for different ship types and operational cases. For medium and long distance waterborne transport, the HyMethShip concept is considered the best approach available that achieves this level of CO2 reduction and is economically feasible. The HyMethShip consortium includes a globally operating shipping company, a major shipyard, a ship classification society, research institutes and universities, and equipment manufacturers. Further stakeholders will be represented in the External Expert Advisory Board and will be addressed by dissemination activities respectively.