In response to your "ferry" question, we have visited Malta, Sicily and Sardinia and travelled to all three by ferry. Frances is a Zine expert on Malta so I defer to her but will say that we enjoyed our stay there, visiting Malta island and spending a day on Como. For both Sicily and Sardinia you would ideally need a car to visit. Transportation on Malta is easy.

We ferried from Civitavecchia to Sardinia and spent about five days touring the island. The interior is hilly and somewhat wild. The eastern shore line is beautiful - the beaches are great. We stayed in Cagliari, which didn't impress us; in Algheri, which we enjoyed; and in Muravera, a tiny town on the sea, which we thoroughly enjoyed. Food in Sardinia is wonderful.

We ferried from Naples to Sicily and stopped at Stromboli for two nights. At each island stop, we stepped off the ferry for the time it took to unload and load passengers, usually to eat and walk. Generally, we had at least an hour at each stop.

You don't say how much time you have, but IMHO, travelling by sea is a terrific way to visit the Mediterranean islands. Check the ferry schedules to determine how long each leg will take. It may take longer than you think, with the exception of Sardinia-Corsica, which is a short ride.

Enjoy. Lucy, Toronto