I would also caution against thinking that Flights By Celebrity will take care of you in case of a problem. I did a Galapagos cruise with the extension to Machu Picchu with Celebrity last November and booked our flights through Flights By Celebrity because our cruise price included a flight credit (I had to fight with them over the amount of the credit but that's a different story). The night before our flight home from Lima to San Francisco, there was an accident at the Lima airport that shut down the airport since they only have one runway and we were notified via the app that our American Airlines flight was cancelled, along with all other flights that were leaving the next day. We asked our Celebrity tour guide if we should rebook our flight directly with AA or if Flights By Celebrity would take care of it, and he advised us to wait for Celebrity to do it, and told us he would contact Celebrity to see if they would handle the necessary extended hotel stay. In the meantime I was checking in the AA app periodically and noticing that the flight options for us to rebook were rapidly going away. After not hearing back from our tour guide for an hour and noticing that all remaining flights that entire week were no longer available, I finally got through to AA by phone and rebooked us, but by then the first flight out was 3 days later, which wasn't even available to us on the app. We had to pay for the extra hotel nights on our own. Many hours later, we finally got an email from Flights By Celebrity that simply restated the flights we had rebooked ourselves. Had we waited for Celebrity to rebook us, we probably would have had an even longer delay getting home.