A stronger version books nights in Rome after the cruise rather than relying on the port call alone: sail Barcelona to Civitavecchia via ports like Marseille and Naples, then disembark and stay in Rome for two or three days before flying home.
One port day is not enough for Rome
Civitavecchia to central Rome is roughly an hour each way. Pick one area, ancient Rome or the Vatican, for a port day, and save the rest for a proper stay at the end.
Three ways we’d do it
Fly-cruise · 10–16 days
Barcelona + Mediterranean Cruise
Fly to Barcelona, settle in for two nights, then sail the western Med.
Barcelona → Naples → Civitavecchia → Rome
Coastal escape · 7–10 days
Amalfi Coast Escape
Naples, clifftop Sorrento and the lemon-scented villages of the Amalfi Coast.
Naples → Sorrento → Amalfi Coast
Rail journey · 12–16 days
Italy Without Flying
Milan → Florence → Rome → Naples, all by fast train.
Milan → Florence → Rome → Naples