by Andy W » 28 Oct 2014, 14:39
The two sailings on Blue Star per week are "lifeline" routes subsidised by the government and operate year round. The days of the week may vary though. Dodekanisos Seaways have a weekly sailing from mid-May round to mid-October, usually, but not always, on Wednesdays.
That's as good as it gets, except:
Kastellorizo has an airport! There are five domestic flights a week from Rhodes operated by Aegean/Olympic using smallish 30 seat planes. These flights are subsidised and you probably won't find timings for next summer yet, as the contract has yet to be awarded for then, but normally nobody else tenders...