Special buses leaving from the central bus station bring you to a number of ferries in Friesland and Groningen departing from small seaports to the islands north of Groningen: Schiermonnikoog, Ameland, Terschelling and Vlieland, and the German island Borkum.
Information on ferry timetables is available at the main bus and railway stations. The main Groningen bus station is located next to the main railway station.