Does your cruise ship not have a “Florence on your own” kind of shore excursion, that is, a bus trip that takes you to and from with the guarantee of making the ship? If so, I would seriously consider that because the traffic and length of time getting to and from can be rough. You also may want to look on a website like cruisett.com to see how many ships will be in port that day. If there are a lot, you’ll be competing against a horde of people for public transportation. Last year, coming back from Pisa to the port of Livorno, we ran into some amazing traffic that made us almost an hour late and necessitated us being dropped off right at the ship just before it sailed. Since Florence is much further away the potential is there for traffic to be even more of a problem. Also it really depends on what you like. My husband and I went to Florence a few years ago and spent three days there and while we liked it, it was not the highlight of Italy for us. On the cruise last summer, we spent a half day in Pisa and were surprisingly pleased with the tower, baptistery, and cathedral. I have also heard really good things about Lucca. So either of those towns may be a better choice for you than Florence. Or, if not better, more practical for what you can accomplish in a short period of time.
