Every ship generates a significant amount of operational and performance data. When appropriate arrangements are in place, this data can support a range of activities, including vessel performance monitoring, voyage optimisation, weather routing, and other energy efficiency initiatives to the benefit of individual parties and the wider shipping industry. BIMCO's Energy Efficiency Data Sharing Clause for Time Charter Parties 2025 provides a contractual framework that enables owners and charterers to share data, while also facilitating the involvement of authorised third party service providers where required. This article sets out the case for incorporating the clause into time charter parties as good commercial practice, with particular attention to the role of the nominee and its significance for voyage optimisation and weather routing companies. The data gap holding performance back A standing problem in vessel performance, weather routing, and voyage optimisation is that recommendations often have to be made on the basis of incomplete information. Noon reports submitted once a day, speed and consumption estimates derived from contractual warranties, and weather data overlaid on approximate positions remain, in many cases, the operational reality. Most vessels generate a continuous stream of high frequency sensor data, including shaft power and RPM, fuel flow rates, speed through water, draft, heading, and wind speed and direction, often sampled at short intervals. This data is logged, but without the right contractual framework in place, it rarely reaches the people who need it. The BIMCO Energy Efficiency Data Sharing Clause 2025 addresses this gap. What the clause does At its core, the clause sets out a structured and legally sound mechanism for sharing onboard sensor data between owners, charterers, and their appointees, the term used in the clause for authorised third parties. This includes service providers such as weather routing companies, voyage optimisat