To reduce greenhouse gas (GHG) emissions in line with International Maritime Organization (IMO) regulatory net zero milestones towards 2050 requires step changes in technology and fuels, and won't be achieved through incremental improvements. Ship owners are facing a number of technology options, but must consider these in the context of performance and feasibility of integration, without adversely affecting operational capability, risk and commercial viability to an unacceptable degree. Without this practical consideration, on-ship adoption of cleaner technology may be slower and higher risk, and therefore also deter investment by technology providers. To reduce challenges, this consortium believes that, in parallel with cleaner energy technology-readiness level (TRL) progression, the key lies in SRL and ORL -- systems- and operational readiness levels - to de-risk adoption and focus on real functionality and impact. SRL involves proving physical integration and interfaces, automation and control of system behaviours and functionality within the platform's mission or duty cycle. This project focuses on addressing barriers to adoption of fuel cells on a real, large ship application, potentially accelerating adoption, evaluating: * how a fuel cell can be applied to marine applications and safely integrated into a ship's operational functionality * how a fuel cell can be integrated into a larger ship's power and propulsion architecture and layout * trade-offs, and how the new technology compares with current ship functionality and performance * impact on reducing emissions compared with today's baseline * a roadmap to implementation.