Grassroots innovations are seen as important contributors to sustainability transitions, however, given their dependence on place-specific conditions they face diffusion challenges. Responding to previously outlined gaps regarding conceptualisation and exploration of the spatiality of grassroots innovations, this paper introduces a conceptualisation of nomadic grassroots innovations. These are grassroots innovations that are mobile and perform activities in multiple places they continuously return to, conceptualised as host localities, while also being based in home localities containing for example offices and key infrastructure. Contributing to a more nuanced understanding of the geography of grassroots activities, the analysis explores the spatiality of socio-technical elements influencing three stages of development (initiation, operations, and upscaling and diffusion) of nine grassroots initiatives promoting a return to traditional sail cargo ships. Findings suggests that nomadic grassroots innovations are dependent on elements in home and host localities as well as from national and international contexts, indicating that the spatiality of nomadic grassroots innovations differs from place-based initiatives throughout all stages of development. Furthermore, analysis of challenges and opportunities for development of nomadic grassroots innovations reveals three key learnings for grassroots innovation diffusion: strategies for developing social cohesion through multi-scalar actor networks, utilising (costumer) demand for alternative solutions, and taking favourable sector conditions as a starting point when designing grassroots innovations. Combined, this could enable development of grassroots innovations that are less dependent on place-specific conditions and thereby easier to replicate, which could increase the capacity of grassroots innovations to tackle global challenges such as climate change.