Here is our experience getting from Bari Station onto the Jadrolinija overnight ferry to Dubrovnik, which caused us some difficulties - buying the ticket over the internet was the easy part. The hard part was exchanging the internet ticket receipt for the boarding documents and finding out where to do this.
Outside Bari station is a tourist information service. This was unattended but a sign advised that bus 20/ (the slash is important) for one euro goes to the ferry terminal. There was a separate ticket office which sold the tickets.
The trip to the terminal takes about 10 minutes. The port area is secure and the bus passes through the only tourist entrance.
The terminal was a large cavernous building, largely uninhabited. We arrived rather early (about 16:30 for a 22:00 departure) and found a luggage depot opposite the terminal which looked after our luggage for 8 euros.
Signs at the terminal say the Croatia departures are from the first floor. This was incorrect. On the ground floor is a Jadrolinija office whose attendants refused to answer any questions and referred us to the information desk opposite. Here we were told there is a regular shuttle bus running every five minutes back and forth from the terminal to a Jadrolinija office on the waterfront about 3 kilometers away where the internet printout must be exchanged for boarding documentation. The bus ran starting 18:00.
The Jadrolinija office is supposed to open at 18:30 but actually opened somewhat later. We decided to wait near the counter prior to opening which turned out to be a good move because a long queue quickly formed behind us and the three guys in front of us took about 15 minutes to process once the window opened.
Boarding started through the back of the ground floor terminal hall at 20:00 through an emigration checkpoint whose attendants were far more interested in joking around with each other than actually processing passengers. Once out on the wharf we boarded the ship through the car loading ramp. There was an attendant who showed us to our cabin. This I must say was very clean, spacious and comfortable. Your luggage goes into the cabin with you.
We had time to kill during this long process and got a map of the town from the information point in the terminal. The old town with its Norman Castle, old cathedrals and narrow cobbled streets is just a short walk from the terminal. It is one of the most fascinating parts of Europe I have been to, and completely unspoilt by tourism. Quite safe, but a real maze where we quickly got lost. However it is a relatively small area surrounded on three sides by water and once you get to the water it is easy to orient yourself. If you pass through Bari without seeing the old town you are really missing an experience.