Data collection on population size and distribution of cetaceans in Sicily, Ionian Sea, promoted by the MareCamp association thanks to the citizen science initiative \"Report a sighting and help the research\" through phone and e-mail communications made by yachtsmen and fishers, and also filling in the following online form https://forms.gle/mAx9ZHZDzrPfs9P59 Data here provided were collected in 2008-2019 period. The project is ongoing; sightings are reported in the database only if the advisories have good photos of reference able to distinguish the species and the area of observation. Presence of boats, fishing activities, other species like birds, fish, jellyfish, meteorological and sea conditions are also collected.