International shipping is among the hard-to-decarbonize sectors in global value chains (GVCs). We investigate how actors in maritime transport address the environmental upgrading of GVCs to navigate the long-term energy transition. While most environmental upgrading literature focuses on changes at the firm-level, in many industries systemic changes are required. We aim to address this gap in the literature, and find that actors aim to navigate technological, political, market and financial uncertainty, in order to escape a so-called “fuel roulette”. With ports and other maritime value chain actors as the focal point of the study, our research draws on data from two main sources: three field-configuring events in the sphere of maritime industry and the energy transition, and fifteen expert interviews. We contribute at the nexus of environmental upgrading of GVCs, maritime economics and temporality literatures, by opening up the role of ports and other key GVC actors in maritime energy transition and by shedding light on the environmental upgrading process of GVCs through a temporality lens.