<p>Solar fuel synthesis is a potential technology to produce storable and transportable energy carriers and net-zero chemicals. However, solar-powered circular chemistry will require large areas of land, which are often prohibitively expensive, needed for agriculture or housing, or politically inaccessible. Shifting from land deployment to solar chemical production on open water bodies thus provides an attractive alternative to overcome the challenges associated with land installations. This Perspective presents concepts, prototype devices, deployment scenarios and the advantages of floating solar fuel applications on water compared with conventional land-based systems. Inspired by the promise of floating photovoltaics, we discuss both floating platforms and self-floating solar fuel devices, along with the opportunities they offer to improve the societal and economic benefits of solar fuel synthesis. We believe that solar fuel production on open water deserves serious consideration, as it can overcome the limitations of land-based deployment and enable decentralized, mobile deployment around the world.</p><p></p>