Sikinos is the quiet one. Sitting between Ios and Folegandros, it has a small hilltop Chora, a few beaches and a harbour that only a handful of ships call at each week. From Santorini it is an easy escape from the busiest island in the Cyclades to one of the least visited, and the fare is about the lowest you will find anywhere in the group.
The crossing is short but not tiny: about 2 hours on the Fast Ferries ship and a little less on the Maistros Santorini boat. Both are slow, simple services rather than high-speed catamarans, and neither sails every day, so this route is about picking the right day more than the right time.
Our older route data listed Blue Star Ferries and Seajets on this crossing. Ferryhopper's more recent figures show them sailing only in the opposite direction, from Sikinos to Santorini, while the Santorini to Sikinos direction is served by Fast Ferries and Maistros Santorini. We have used Ferryhopper's figures throughout.
Before you go, book somewhere to stay and ask how to get from the port up to the village; Sikinos is small and quiet, and a late arrival is easier with a plan. Keep your return in mind too, as boats back are also limited to a few days a week per company.