Amalfi Coast

If by "cruise" you mean a large ship with a buffet, swimming pool, etc., I'm not aware that one exists that just covers the Amalfi Coast (it's too small an area to have full cruises). This would be like a cruise that only went from Los Angeles to San Diego. But there are boats from Naples that go to Sorrento, Amalfi, Positano, and Capri, which are for transportation rather than a "cruise ship experience." The trips are too short to have or need amenities or entertainment, but you certainly could get great views of the area this way. Rick Steves Italy book has details of the boats in this area. Be aware that they run from April or May to September or October, and that they can be canceled in bad weather. If you have other cruise questions, the site http://www.cruisecritic.com/ is the place to get them answered.

You can get day cruises from Sorrento around to the town of Amalfi. http://www.goldentours.it/en/blue_mini_cruise.php Or far more expensive, a private charter excursion. Ypu can also charter a boat for a number of days, even more expensive. http://www.nauticasicsic.com/en/boat-excursions.html AFAIK there are no ferry services from Naples to the Amalfi Coast this year just the usual commuter services to Sorrento and the Islands- financial cutbacks.