How to reach Crete island

Crete by plane

Athens - Heraklion : approximately 7 daily flights
Athens - Chania : approximately 4 daily flights
Thessaloniki - Heraklion : approximately 2 flights per week
Thessaloniki - Chania, Rhodos - Heraklion : between 3 and 5 flights per week
Some flights especially in summer since Mykonos, Paros, Santorini, Karpatho (for Sitia), Kasos (for Sitia)

Crete by boat

From Piraeus, towards Heraklion and Chania: each day, approximately 12h. One or more times per week, these ferries pass by the cyclades islands (Sifnos, Paros, Naxos, Ios, Santorini)
Since Santorini, each day in summer
Since Thessaloniki, approximately 3 times per week in summer for Heraklion. There are also ferries, especially in summer, from Karparthos, Kasos, Rhodos, Sitia and Santorini.