Santorini to Heraklion is the bridge between the Cyclades and Crete, and one of the most useful ferry links in the southern Aegean. It lets you pair a few days on the caldera with Crete's mountains, Minoan sites and long coastline without going back through Athens. Heraklion is Crete's largest city and its main port, and it has an international airport (HER), which makes it a practical place to end a Greek island trip.
The two ports are about 63 nautical miles apart, and the way you cross depends on your priorities. Seajets runs fast catamarans that cover the distance in around an hour and a half, while Blue Star Ferries uses big conventional ships that take roughly three hours or a little more but cost a fraction of the fare, from €15 when we checked. The Blue Star ships also have cabins, which matters because some of their sailings leave Santorini around midnight.
This is open water, not a hop between sheltered neighbours, and it is worth taking seriously in the windy months. The high-speed boats feel the swell more, and people prone to seasickness often prefer the larger ships. On the other hand, the fast boats make the crossing during the day and leave you the afternoon in Crete.
Before booking, sort out how you will get down to Athinios, Santorini's main port under the caldera cliffs, where all Crete ferries leave from. The single road to the port gets congested in summer. At the other end, Heraklion port is close to the city centre and only about 5 km from the airport, so onward travel on Crete is simple.
