The Republic of Croatia, as a Mediterranean country with an indented coast has an archipelago with more than a thousand islands, which is a recognizable market potential of Croatian tourism. Because of the natural values, a particularly valuable and successful part of Croatian tourism and the potential of islands development is the development of nautical tourism. The indicators of the quality of nautical tourism and the nautical tourism quality management system have not been sufficiently studied yet. The basic principle of nautical tourism development management is the principle of sustainable development, which in a compromised and balanced manner is a pre-condition for analyses of the need to preserve the natural environment and the need for economic development. Strategic documents of the Republic of Croatia define "nautical tourism as a special type of tourism which apart from navigation in private organization -cruising by one's own or leased vessel with onboard accommodation and/or sleeping of tourists, includes also cruises in the organization of vessel owners and travel agencies with accommodation and/or sleeping of tourists onboard these vessels, and navigation of tourists onboard vessels for the purpose of other forms of holidays and recreation (fishing, diving)." The paper will implement the multi-criteria decision-making methodology in selecting the criteria and sub-criteria of the nautical tourism development model. The influence of criteria, sub-criteria and alternatives on the function of objectives, i.e. the development function of islands, and the assessment of influence of factors will be determined. The research results are based on the expert assessment and input data on the system (elements, characteristics) of nautical tourism of the Republic of Croatia.