Are you saying you need to be at the airport at 8:30 a.m. the day you get off the ship? If so, that is a huge problem.
offers a coach between Termini and Ciampino airport.
The fast train takes about an hour from the port to Termini and on the day we took it Dec.1 it was running 45 minutes late. so you need to give yourself plenty of time. To get from Termini to Ciampino I would say 30-40 minutes in normal traffic. There is a train that goes from Termini to downtown Ciampino but I am not sure of the schedule and you would need to take a cab from the train station to the airport.
Ciampino airport is small and make sure if you want to grab a bite there or something to drink that you have some euros left as they do not accept credit cards in the snack bar and there is only one ATM in the entire airport and it happened to be out of order when we were there :evil:
God luck and have a good time.