From mid-May to early September, the vintage vessel Helge sails to Valdemars Slot (60kr, 55 minutes). En route it makes four intermediate stops. First is Vindebyøre (30kr, 10 minutes), handy for Svendborg Sund camping ground, then the popular beach area of Christiansminde (30kr, 15 minutes), pretty Troense (60kr, 30 minutes) and Grasten on Thurø island.
The boat leaves Svendborg harbour at 10am, 12.30pm and 2.30pm with extra July departures at 4.30pm, 6.30pm and 8.30pm. You can use it as a long sightseeing tour (60kr one way) or a short-hop transport option (riding two stops for 30kr).