Research vessels are often the only mean to conduct research campaigns at sea or in remote locations. Research vessels can be classified according to their mission (instrumentation carried onboard, laboratories, etc.) and according to their class. It is possible to distinguish between ships devoted to hydrographic research, oceanographic research, fisheries research, naval research (mines, submarines detection), polar research, oil exploration. These categories are not mutually exclusive, thus, often research vessels are multi-role. It means that are equipped or can be reconfigured to carry out different missions. Considering vessel size, four different classes can be identified: the Global, Ocean, Regional and Local (IWG-F 2007, EurOcean 2021). Reference particulars for each class are provided in Table 1 along with the number of research vessels active in European fleets.