You probably can board ship at 11, though usually it is 1 or 2 pm before you can get into your stateroom.
One thing we enjoyed in Ft. Lauderdale, if you are in no hurry to get on ship, is you could visit Butterfly World. It takes about 2 hours.
Equal opportunity cruiser since 1998-4 Carnival, 4 RCI, 3 HAL, 3 Princess, 5 Celebrity, 3 NCL, 1 Disney
I have now achieved-
ONE HUNDRED DAYS ON A CRUISE SHIP!!!!!!!!!!
146 days total