Vis Ferry Port
The Vis ferry port is located directly in the center of Vis town, the port is not very big so before arrival and departure of the car ferry, it can get pretty crowded especially in the main summer season.
Near the port, you can find kiosks, supermarkets, coffee bars, restaurants and fast food places, so killing the time while waiting for the ferry should not be a problem.
Getting to Vis Ferry Port
If you are staying in Vis town, you can walk to the port, even if you stay in the eastern part of town it is a maximum 1 km distance.
If you stay in Komiza on the other end of Island Vis, you can take the bus which departs so that you can be in Vis in time to catch the ferry or catamaran, from most other parts of the Island you will have to arrange transportation on your own to Vis town.