Device to be attached to a vessel, preferably a boat, for cleaning of floating collars (2) on net cages, optionally having a bottom ring (3). The device comprises at least one wheel pair (4a, 4b 5a, 5b) attached to a supporting device (6 7), and at least one upwardly nozzle (14) arranged before or after the wheel pair. The floating collar (2) to be cleaned is bearing against the top side of the wheel path and is guided over said one or more nozzles.