I arrive in Rome on a Saturday morning (not sure exactly when the cruise gets to Port). This is the end of 1 week cruise. I will be in Rome until Monday afternoon and then traveling to Florence. While in Rome I would like to visit the Vatican and Coliseum. My cruise was originally supposed to stop in Naples and was going to do a Pompeii tour but just found out that there has been a change in the itinerary and we will not stop in Naples. Is it doable to do Pompeii in a day from Rome? Also can you visit Vatican and Coliseum in one day? Looking for suggestions on how I can do Vatican, Coliseum and Pompeii in 2.5 days. Wondering if I should go directly to Pompeii when I get off the ship on Saturday and then go back into Rome that evening, then do Coliseum Sunday and Vatican Monday OR do Vatican and Coliseum on Saturday when we get off ship, go to Pompeii Sunday and then back to Rome and off to Florence Monday OR do Pompeii Monday and go directly to Florence from Pompeii. I’m confused and want to do so much in those 2.5 days but not sure if it’s realistic. Any suggestions would be appreciated!!!
I assume your cruise port is Civitavecchia, which is north or Rome while Pompeii is well south. The Rome2Rio website estimates the train would take 3-1/2 hours from Civitavecchia to Pompeii, with a change in Naples. I wouldn't attempt that on Saturday. Who knows what time you'll actually get off the ship? Then you'll have to get to the train station, and you'll have luggage to deal with. I'd plan to get an early start on Sunday and do Pompeii then--if you feel Pompeii justifies the approx. 7 hours on the train. It may (I haven't been there), but I've seen knowledgeable folks here recommend Ostia Antica to people staying in Rome who were considering Pompeii. Ostia is very nice and readily reachable by public transportation from Rome. Substituting Ostia for Pompeii would free up many hours for extra sightseeing in Rome. I don't know whether a bus tour would get you to Pompeii any faster than the train. It would certainly cost more.
To see the Vatican Museums, not just St. Peter's, you'll need to pre-book since your time is limited and you can't afford to spend a lot of time in line. If I'm interpreting the website correctly, the Museums are closed on Sundays except for the last Sunday of the Month, when they're open until 2:30 PM. They are closed on June 29, however. There are different paths through the Museums; some taking a lot more time than others, so you should check out that information online to see how much time you'll likely need before trying to make a reservation. But since this is a must-see for you, try to get that reservation taken care of soon. Worst case, you can go to the Vatican twice, seeing St. Peters and the Museums on different days. (There are, of course, tours of the Vatican that you can take if you're willing to spend the extra money.)
You should have time for the Colosseum on Monday before you leave for Florence or, if that's your day at the Vatican, on Saturday afternoon.
You can see the Vatican Museums and Saint Peter's Basilica on the Saturday afternoon that you arrive (get as late an appointment as possible for the museums, the basilica is open until 7pm, I think).
On Sunday you can visit Pompeii, but that's a long day, and the Colosseum may be closed on Monday. You could visit the Colosseum and Ostia Antica on Sunday.
The best I can tell from a quick check of online info, the Colosseum is open on Mondays, but that is a common museum closing day in Italy. It's good to keep that in mind.