Nautical tourism is considered a specialized branch of tourism, specialized in providing nautical services to end users. It is becoming more attractive around the world and is recording higher growth rates and higher revenues every year. Comparing the development in the world and in our country, it can be seen that the disparity is in the speed of its development, given that in the Republic of Croatia nautical tourism in its beginnings developed at a rather slow pace. Marinas in the Republic of Croatia have been recording more and more successful business from year to year since their accelerated development beginnings. For the analysis of marina operations in the Republic of Croatia, data from 2017- 2020 were taken. The Republic of Croatia is recording an increase in the number of nautical tourism ports from year to year. For example, in 2017 there were 140 ports, and by 2020 that number had climbed to 185. Marinas in the Republic of Croatia are richly equipped, the offer is varied, from smaller to larger, and every boater can find what suits him. The level of quality in most marinas and ports is satisfactory, but there is always room to improve supply and quality. It is clear that this is a promising form of tourism, which he has proven over a 20-year period, but it is important to follow trends and improve supply in line with demand, but also always be one step ahead of tourists, devising innovative solutions. Nautical tourism in the Istria County is certainly an important segment of developing the destination offer, as well as its improvement and innovation, and is based on 4 major ports: Umag, Rovinj, Pomer and Pula, which are the subject of a case study. The following data were analyzed: number of ports by categories, capacities, number of employees, number of vessels at permanent berth at sea and on land, number of vessels in transit and generated revenues for the observed period 2018, 2019 and 2020.