Generally walk offs start leaving the ship between 7:00 and 7:30. Arrange to walk off and carry your own luggage off the ship. They usually only permit you to have one piece of luggage if you are taking it off yourself, so if you have more get prior okay from guest relations. Same thing happened to me. I took a transatlantic on the Liberty OTS to Ft Lauderdale. I walked off, took a cab to Ft Lauderdale airport and was checked in before 8:15.