While most hydrogen research focuses on the technical and cost hurdles to a full-scale hydrogen economy, little consideration has been given to the geopolitical drivers and consequences of hydrogen developments. The technologies and infrastructures underpinning a hydrogen economy can take markedly different forms, and the choice over which pathway to take is the object of competition between different stakeholders and countries. Over time, cross-border maritime trade in hydrogen has the potential to fundamentally redraw the geography of global energy trade, create a new class of energy exporters, and reshape geopolitical relations and alliances between countries. International governance and investments to scale up hydrogen value chains could reduce the risk of market fragmentation, carbon lock-in, and intensified geo-economic rivalry.