Designing autonomous public transport requires understanding how passengers experience such systems in real-world use. For autonomous ferries, however, little is known about how users interpret waterborne autonomy. We address this gap through post-ride interviews (N=164) from a public trial of an autonomous ferry held in Trondheim, Norway, in 2022. Our thematic analysis identifies several ferry-specific factors that shape the user experience (UX). The themes were formed around sensitivity to motion and docking, the readability of manoeuvres without a visible operator, expectations around on-demand timing, and accessibility challenges at the vessel-quay interface. From these findings, we propose six design guidelines that address embodied experience, transparency of autonomous behaviour, temporal predictability, accessibility across travel chains, and the redistribution of social informational roles traditionally held by the crew. These findings extend land-based autonomous vehicle research by revealing how waterborne contexts shape trust and acceptance. The contribution of this work is a set of actionable design guidelines to achieve a predictable, trustworthy, accessible, and reliable autonomous ferry service.
ACM CHI Conference on Human Factors in Computing Systems