Hellenic Seaways is the only carrier of passengers between the Hydra Island and the mainland. Hydra is on the route that also includes Poros, Spetses, Porto Heli and Ermioni. What is included on the route depends on the time of day that the flying dolphin or cat leaves. You can find the timetable, routes and ticket prices at their site www.HellenicSeaways.gr as well as an online booking service. On Hydra the ticket office is situated at the end of the quay where the big cats dock.