Traveling from the port
The Public Buses to Fira meet most of the ferries (not all, but some of the big ones). After the bus is full and leaves the port someone comes around to collect your money. To be sure that you get a seat on the bus you need to try to be in the first wave of people getting off the ferry, although this may not be such a problem in winter.
All the buses at the port go straight to Fira (Thira, the capital of the island). Once you reach the Fira bus square you need to catch the next bus leaving for your village of choice. Any changeovers for the next bus destination must be made from the main station only in Fira (Thira).
Also, there is no direct service between santorini port and airport.
Traveling to the Port
Buses to the port leave Fira about an hour before the regularly-scheduled departures of the ferries leaving Santorini for other islands. You will see a schedule posted outside the little building at the bus square.
At the port, there is a taxi station, where the cabs are waiting after the ferry arrival, although many of them have been reserved in advance. All cabs are gray and have a lit ‘taxi’ sign on top. Taxis can sit up to 4 passengers although they might not be able to take that many suitcases. If you are a larger group, you need to take more 2 or more taxis and travel separate. Extra charges will be applied for overweight baggage, port or airport pick up and night transfers.
Shuttle and Private Transfers
Shuttle service is more affordable than taxi transfers and the rates are always fixed. Here is a local transportation company offering both private and shared transfers for small or large groups. http://www.santorinitransport.com