There are numerous services between the port of Turku and the Finnish capital Helsinki each day. If you are travelling to Turku satama, there are fewer services, but still a few in each direction per day. If you are heading to the port make sure you book it for Turku Satama, rather than just Turku.
The journey is made on-board double decker InterCity trains, and connect Helsinki with ferries to Sweden.
Local bus and train services are avalable from Karjaa/Karis to/from Hanko. The journey takes around 40 minutes by train, or 50-60 minutes by bus. Services are available roughly every hour.