Integrating autonomous technology for waterborne vessels is gaining momentum with several services launched in recent years. However, compared to other autonomous public transportation modes, passenger intentions, key influencing factors, and variations across different user segments remain underexplored. Our work addresses the research gap by focusing specifically on tourists, contrasting with the prevailing literature emphasis on economic aspects of cargo vessels. This study investigates intentions to adopt autonomous boats at Kaohsiung’s Love River in Taiwan through a pre-trial on-site survey of 491 domestic visitors. The findings reveal that perceptions of performance effectiveness, ease of use, and enjoyment significantly drive adoption intentions, while concerns related to unfamiliarity and anxiety about new technologies inhibit acceptance. Utilizing an extended Unified Theory of Acceptance and Use of Technology (UTAUT2) model, structural equation modeling, and response-based segmentation (REBUS), three distinct user segments were identified: Pleasure Seekers, Cautious Enthusiasts, and Skeptics, each characterized by varying levels of enthusiasm and apprehension. This research contributes to transport and tourism literature by providing deeper insights into tourists’ acceptance of autonomous boats, emphasizing the roles of performance expectancy, hedonic motivation, and psychological barriers. Conceptually, we extend the UTAUT2 model with Technology Interest, Anxiety, and Trust. We apply REBUS-PLS to analyze heterogeneity, providing new methodological directions. The practical implications offer valuable insights for policymakers and operators to develop targeted marketing strategies and policies, foster user acceptance, enhance safety and emotional assurance, and effectively promote the distinctive experiences provided by autonomous maritime tourism.