Take into account the number of stops and the arrival time: Sometimes a ferry that leaves an hour later gets you there faster! Catamarans and hydrofoils are pricier, and you need to reserve in advance in summer, but they cut travel time in half. Remember that if the sea is choppy sailings are often canceled. The main ferry line is Hellenic Seaways; the main booking engine is www.greekferries.com. Check out our Greek Island hopping itinerary.