We just got back from our cruise and had originally purchased bus and train tickets to get us from Rome to the port.
Unfortunately, we missed our connection in Lisbon and spent over 14 hours there which forced us to book the Airport Hilton, cancel our previous reservations and come up with alternative transportation.
Since it was last minute, I thought for sure it was going to be a nightmare. I found Shared Shuttle online and reached out, thinking there was no way they'd be able to accommodate me on such short notice, but they did!
It was very reasonable, and super easy. In fact, we were so happy with it, we ate the cost of previously purchased bus and train tickets and booked them to get us from the port to Rome on debarkation day. It was totally worth it and we will be using them every time we go back to Italy!
You can find them here:
https://sharedshuttle.it/