The Thomson Calypso is a tiny (11,000 tonnes) adults only ship. One of its 7 day itineraries is from Thessaloniki through the Corinth Canal, on to Zakynthos, Corfu and then two mainland ports - Itea and Volos. Apparently it is the largest vessel that is able to navigate the canal. Going through the canal takes place during the afternoon on the day at sea (day 2) and is a fabulous experience with everyone out on deck. The return through the canal is during the late evening/early hours of the morning and just as much an experience as, in places, there are only inches to spare on each side. The ship has limited facilities but provides a very good value cruise experience - mostly down to the crew and staff and the ports it is able to visit.