There are regular buses from Naples train station to the ferry ports in Naples.
If you arrive by train at Naples Centrale train station and want to take a ferry to the Amalfi Coast or nearby islands like Capri and Ischia, you can take a city bus from the station to the ports.
To do this, first buy a bus ticket from a news stand in Naples Centrale. Tickets cost less than 2 euros for a single, and can be validated in the yellow machines on the buses to the ports.
Next, exit the station and walk straight through the large parking lot until you come to the end. Cross the street and wait at the bus stop for Naples city bus R2 or 601. The bus will be either an orange accordion bus or a regular grey bus. Buses can be very crowded, so be prepared to stand and watch your belongings carefully to avoid theft.
The bus journey from Naples train station to the ports take around 10 to 15 minutes, depending on traffic.
Get off the bus at Piazza Municipale. From there, cross the street and go towards the port. If you are going to Naples Molo Beverello ferry port, cross the busy street at the end of the road and turn right. The port will be a short distance up the road.
If you are going to Naples Mergellina ferry port, follow the same directions but don’t make the last right turn. The port will be straight ahead after you cross the street from where the bus from Naples train station to the ferry ports dropped you off.