Donousa is the island people leave reluctantly. It sits alone in open sea off the east coast of Naxos, about 15 nautical miles away, with a harbour village, a few hamlets, footpaths over bare hills and some of the clearest water in the Small Cyclades. Getting back to Naxos is how most visitors rejoin the wider ferry network, because Naxos is the big, busy hub of the central Cyclades, with an airport and boats to Piraeus, Paros, Santorini and beyond.
Your choice on this crossing is simple. The Blue Star ship does it in around an hour for a fare that started at €6.50 when we checked. The little Small Cyclades Lines boat is almost as cheap, from €8, but it takes roughly three and a half hours longer, because it threads its way back through other islands of the group before reaching Naxos. On a calm morning that slow route is a free cruise; with a deadline or a queasy stomach, take Blue Star.
Neither company sails every day on its own. In Ferryhopper's table of last year's sailings, Blue Star ran this direction on 3 or 4 days a week and Small Cyclades Lines on 3 or 4, which together cover most days. So the question is less "which boat" than "which boat runs on my day", and that is worth settling before you book your last night on Donousa.
If Naxos is only a stepping stone, give yourself room. Wind can hold the boats, and with a few sailings a week a delay can cost a full day. A night in Naxos Town before a flight or a Piraeus ferry is cheap insurance, and a good excuse for dinner in the old town.
