There is also a free bus from the dock gate to a shopping centre.

There is a nice market in Civitavecchia. If Rome is too much of a hike then take a short train ride to next stop along to nice Seaside resort Santa Marinella.

Well. I think it all depends what you like. I asked a similar question on this site a few weeks ago, as we know Rome well so weren't inclined to bother with the trip there just for a few rushed hours. I had useful answers from a couple of kind people (try putting Civitavecchia into the search facility on this site). We spent a happy half day there and found it to be a very pleasant little town with a market, walks along the seafront, cathedral etc. As one of the people who replied to my question pointed out, you can also take a very short train journey to a nearby beach.

Not much to do in Civitavecchia. Its an industrial port. Catch the train down to Rome from Civit. Station. Quite cheap, and takes approx 44 mins to St Peters. Did it in May.Taxi fare from Civit port to Station 15 euros. A free bus is also available.

Very easy to DIY - Try google and 'cruise ports call boards' - the first result will give you all the info under the Europe section