The ship docks far enough away from any sights that one had to take a shuttle to downtown, MSC charged $15 euro, this got us within easy walking to the Port Vieux, the old historic port area. The day we were there it started to rain so we jumped onto one the small tourist train affairs and got to see more sites with a little information as well.
Tunis was a bit of a disappointment, the ruins of Carthage were interesting but the way they package it at least on the tour we had not very inspiring. We also had bad weather the night before which delayed the ship and so our guide seemed to be rushing us through the small sites we did get to see. there was to be a museum visit but due to the delay and a 6pm closing we could not go in. Also went to Sidi Bou, billed as a city settled by Andalusian arabs. Well again it seem more a tourist trap than anything worthwhile seeing. Although they did have a small house museum of a typical Tunisian house and I must admit for the small admittance fee it was pretty informative and it was better than being chased by the junk hawkers on the street.
Malta was great. lots of history, nice people, an overall interesting and beautiful place to stop for a day. We took the city tour of Valletta and Mdina. A super tour with a good guide. For those who didn't take a tour it was a fairly easy walk into Valletta to visit the city.