We arrived at the port around 12 Noon for a 4:30 departure. It was all in the Carnival "Important Docs" booklet the travel agent gave to us. It has all of your coupons for transportation in it.
If you are arriving in Miami the Night before like we did they will most likely have you stay at the Wyndham Miami Airport Hotel like they did most of the other guests we cruised with. Then they sent a bus to pick us up and take us to the Port of Miami and the Paradise. It was very smooth.
So I am going to Miami port in December for another Carnival Cruise. My first one was in August. It was horrible! Arrived at the airport at 12:30 pm for the 4:30pm departure. We finally boarded by 3:30. Same port as you on Paradise I'm sure, but tell me how you managed to get there the day before and stay in a hotel. Did you pay extra for it? What was the name of your travel agency?
I think that if you are coming from the West Coast to Florida they will put you up in a hotel the night before the cruise. I had to take an extra day off (Friday) so we will fly practally all day on Friday, spend the night in the hotel, and get up and go to the ship on Saturday morning. Smart thing to do especially since there is only one direct flight from Seattle to Miami on American. All other airlines you have to make connections through one of their hubs. With the way the weather can be in December, I don't think I would want to do it any other way!