I’ve had lots of requests for details of ferries to/from Symi in the winter. The ferry companies are never in a hurry to release timetables as nearly all the passengers are local and don’t have the same desire to book months in advance that some tourists do.
However, Dodekanisos Seaways have released their sailings for the period 1 November to 31 March. You’ll find the timetable here:
It is basically the same as previous years, with Rhodes-Symi-Kos-Kalymnos-Leros-Lipsi-Patmos and return on Fridays and Sundays; Rhodes-Symi-Kos-Kalymnos and return on Saturdays; and Rhodes-Symi-Kos-Kalymnos-Leros-Lipsi-Agathonisi and return on Mondays. The usual frantic activity around Panormitis Festival time in early November soon drops back to this pattern by mid-November.
Blue Star Ferries have yet to publish the timetable, but the booking system shows that there will for the first time be three ferries each way a week all winter. The Blue Star Patmos will leave Piraeus on Sundays, Tuesdays, and Thursdays, operating overnight and reaching Symi on Monday, Wednesday, and Friday mornings. As expected she then continues to Rhodes and onwards to either Kastellorizo or Karpathos (Wednesdays). Then she returns the same day, leaving Rhodes for Symi and islands beyond to Piraeus at 16:00 (Monday), 17:30 (Wednesday); or 19:00 (Friday). The exact pattern of islands served is different on each day of the week, but they all call at Kos.
More details when the actual timetable appears.