In countries like Brazil, with continental dimensions and an extensive coast, the coastal shipping becomes a natural way of transporting goods. Nevertheless, for many years in Brazil roads have been consolidated as the main way of doing so. Recently, however, the country has enjoyed a revival of the coastal shipping service. In order to compete with road transportation service, it is important to know the relevant attributes considered by the customers of coastal shipping services. This was one of the motivations for this study, as well as the evaluation of each variable ranked by the clients operating in Brazil. The method used was adapted from the models proposed by Parasuraman et al, GAPS (1985) and SERVQUAL (1988), which identify differences between the level of expectations and perception from customers about the service offered. A case study shows that from customer´s point of view there are gaps in some dimensions of quality of the service provided by the company analyzed. The results also reveal a potential application of the model proposed in the study to measure quality level of coastal shipping service in general.