CF is right. We booked our airfare as soon as we booked the cruise. You may be able to get cheaper fares if you wait, but you also may risk not getting on the flight that has a schedule to gets you to the ship at teh early time. Those fill up fast.
As for getting to a 1PM flight, you SHOULD be able to make that. Even if you just go with the flow and get off when they call your tag color, you should be off by 10Am or 10:30am... If you ask for early disembark, you can be off by 8 or 9.
Carnival Cruise Lines:
Fantasy 90, Celebration 95, Victory 05, Conquest 05, Spirit 6/06, Freedom 6/08, Holiday 7/08, Victory 6/09, Valor 9/09, Dream 6/10, Splendor 8/10,Conquest 8/11,Magic 11/11,Triumph 4/12,Spirit 7/12,Freedom 11/12, Triumph 2/13 - The fire cruise, Magic 1/14, Freedom x 2 6/14
NCL Dream October 2006, RCCL Mariner OTS June 2007, Celebrity Silhouette 2013