Urban linear ferry systems are becoming an increasingly popular transport option for cities worldwide. These ferries stop at multiple destinations in a linear route configuration using high speed, high capacity vessels operating on a scheduled timetable, whereby adding to, and complementing existing public transport systems. This study seeks to provide the first international comparison of urban linear ferry systems, investigate why and how these systems have been implemented, and to explore how this innovation occurred. A set of predefined criteria was established and seven systems were selected for analysis: Brisbane, New York, London, Gothenburg, Copenhagen, Hamburg and Bangkok. The analysis was conducted in late 2014 and involved: i) a review of archival materials and reports for each location; ii) geographical information systems (GIS) mapping to compare route structures; iii) site visits; and iv) interviews conducted with key actors involved in the planning and operation of each system. A focus of the inquiry was why and how these systems were developed and the source of the innovations in each city. The study found that these ferry systems have been implemented for a number of reasons further to people moving, including economic development, tourism and city branding. The role of both private and government policy entrepreneurs was critical in explaining how the innovation occurred in each city. Ultimately, an understanding of the larger contextual role that ferries would play and the political championing of such systems helps to explain these transport innovations and the emergence of urban linear ferry systems worldwide.