Hope you meant Sept 11th - the Miracle sails out of Tampa on the 11th, so if you don't show up until the 12th you'll miss your ship!
I'm on that sailing and watching the Carnival website for any possible changes, but unless there is another hurricane out there I don't think we'll have a change.
Carnival Elation March 11
Carnival Imagination Sept 07
Carniival Sensation Dec 06
RCI Sovereign of the Seas Sept 06
Carnival Miracle Sept 05
Carnival Glory Sept 04
Carnival Fantasy Jan 04