Great question! We are sailing out of San Juan this Saturday the 5th on Serenade and wanted to know the same thing. We fly in on Friday night and want to board as soon as possible. Which week are you sailing on the Serenade?
That's correct. I was on Serenade in November with a 10:00 pm sailing and we checked in just before noon. The best part about checking in early is there is no one else there. We walked right up to a window with no wait and were done in minutes.