Normally the ship will give you a survey several days before disembarkation, and also a customs declaration card. If you choose not to carry all your own bags off, you will be given colored luggage tags. you put your bags outside your cabin the night before and they disappear. Disembarkation will be scheduled according to the color. If you specified an early flight on the survey you will probably get tags for an early disembarkation time. If you don't you can go to the Purser's office and usually get them changed by explaining the situation. An early disembarkation time might be about 8:00 or 8:30, sometimes even earlier.
When your tag color is called you disembark and find all the luggage laid out by color in a huge building. You grab yours and either wheel it or get a porter and go through customs and immigration. There is usually not a very big line, and you just show your passport and hand over your card most of the time. Then you get a cab and are on your way to the airport.
So at Ft L, which is normally efficient, you are looking at maybe
8:30 color called
9:00 off ship and in line at Immigration
9:15 out the door and waiting for a cab.
9:45 - 10:00 at the airport with time to spare.
BUT -- WHAT IF --
What if Customs and Immigration delays clearing the ship for some reason ... passenger passport discrepancy, crew document discrepancy, tip received of drug smuggling, or just a maximum inspection policy that particular day.
What if baggage handlers go on strike, or misplace your luggage, or your luggage gets dropped in the water (has happened!)
What if your passport for some reason fails to scan and you are chosen for a particular check? What if your name (or someone with the same name as you) is on "the list"?
What if the doggie alerts on your bag because you brought a sesame seed roll from the buffet and you get pulled over for an extensive search?
What if your cabbie gets in a fender bender with a bus pulling out?
What if there is some computer problem at the airport and 6000 people off of 4 ships are lined up trying to check in?
What if ... what if ... what if....
When you travel, stuff happens. Lots of stuff has happened to us in our 44 cruises, including some of the above. We are more comfortable allowing plenty of time to disembark in a leisurely fashion and not hurry to the airport.
What is the worst that can happen if you do miss your flight? How flexible are you and how upset do you get if stuff happens? How high will your blood pressure go?