Nautical tourism stands out for its potential to achieve social-economic development in coastal and island destinations and as a lever for sustainable tourism. However, the lack of a clear definition of nautical tourism at the international level makes it difficult to characterize it, and the case of Portugal is no exception. In fact, despite the enormous potential of Portuguese nautical tourism, there is a lack of studies that characterize this type of tourism in the Portuguese tourism destination. This paper intends to make a first attempt to fill this gap by assessing the projected destination image of Portuguese nautical tourism with a sustainable marketing approach. In the design of the research, the content analysis methodology was applied. The data were collected from the official websites of the Portuguese legislation and the Portuguese nautical tourism players and analyzed through a theoretical model of sustainable marketing deriving from the literature review. The results provide the sustainable projected destination image of Portuguese nautical tourism and identify the main trends in the legislative framework, tourism activities, networks of players, and support infrastructures for Portuguese nautical tourism. The findings provide practical and useful insights for Portuguese nautical tourism stakeholders aiming to improve a sustainable projected destination image, as well as for researchers identifying research gaps in the nautical tourism topics. This study also provides a new methodological contribution, proposing a theoretical model of the projected destination image of nautical tourism with an approach to sustainable marketing, which can be applied to other nautical tourism destinations.