Further to the last reply, the ferry schedules change in early June, usually somewhere around the 8th. As earlier replies said, there are no fast boats that go directly from Pireaus to Santorini, so that is a non-starter. <BR><BR>Do not confuse hydrofoils with catamarans. They are two completely different kinds of boat. Hydrofoils are small, noisy, smelly, and only serve the short routes, eg Pireaus to the Saronic Gulf islands. Catamarans, such as the Hellas Highspeed 1, 2, 3 &amp; 4 are large passenger and vehicle ferries serving longer routes, such as Pireaus to Paros &amp; Naxos, and Rafina to Mykonos.