This paper aims to assess service quality for ferry transportation (SQFT) using the SERVQUAL measurement scale. The current article integrated the fuzzy set theory into AHP to cope with the subjectivity and uncertainty of the judgments. Next, Importance and Performance Analysis (IPA) was developed to identify priority areas for improvement, maintenance, and potential overinvestment in terms of ferry operations. Besides, some ferry operators (FOs) in the south of Vietnam (hereafter VN-FOs) were investigated to validate the proposed research model. Through the SERVQUAL model, it is found that SQFT includes six dimensions in Layer 1, with twenty-eight service requirement attributes (SRAs) in Layer 2. Particularly, “value-added provision” outranks the service-quality pillars of ferry transport. Moreover, among 28 SRAs in Layer 2, the top four SRAs concern ferry service users the most, including “modern vehicles” (7.59%), “crew helpfulness” (6.41%), “providing internet connection during the journey” (5.67%), and “adequate rescue equipment” (5.63%). Additionally, the IPA model suggests FOs prioritize the allocation of the limited resources for six SRAs with high importance but low performance to improve SQFT. The utilization of the IPA model allows FOs to identify priority areas for scarce resource allocation, thus contributing to decision prioritization within a behavioral framework.