The ferry doesnt start from the 'International passenger terminal' (boats go there to Korea as they told me there). Ships do Dalian start from the 'Yantai Port Passeneger Terminal' which is a bit north west to the train station at Huanhai Road. Also the tickets can be bought there.
I bought a 'sitting' place, so I did only get a ticket for 3rd class. Y180 per Person. With this ticket you can only sit in the 3rd class passenger room where there are a lot of quite ok comfy chairs. Also you can access the deck at the stern of the boat and the dining hall. There some meals are served but you better bring your own food to the boat, hot water is everywhere available. Also there is a little shop on the boat.
There are more comfortable tickets available so youcan get a bed or evenen you own romm ("Touris class" is written on the ferry for those rooms"). But as the ride lasts 7h and if you do it during the day, then you could spare the money for more reasonable things...
Entering the boat there was an elevator to go up, but when leaving you had to carry your luggage down the stairway.
The ferry arives in the north of Dalian. After leaving the ship you get picked up by a bus which takes you in about a 3 mins ride to a dropoff point where also taxis will be waiting. I took a taxi there to Dalian city centre, which takes about 45 mins (if good traffic situation) and Y 66.
All in all the passage from Yantain to Dalian is a nice experience and easy way to travel between these two destinations.