Agathonisi is not directly connected with Piraeus port. So you must first reach Samos or Patmos or Kalymnos, where there is a local timetable, and reach your destination in a few minutes. The island is also connected with Rhodes, Kos, Leros, Lipsi and Arki. The journey from Piraeus to Samos and Patmos takes about 8 to 10 hours.