Most cruise lines' headquarters shut down this afternoon or this evening, with some of the employees staying behind to work in hurricane-proof portions of the cruise lines' headquarters buildings, some evacuated to work remotely, and other functions (such as reservations) to be handled exclusively from offices in farther west in the United States. Those offices themselves were born out of past hurricane scares when South Florida was in the path of storms.
It now appears Irma will arrive in South Florida Sunday morning and at Port Canaveral on Monday. Most cruise lines seem to be anticipating the South Florida ports to be reopening on Tuesday.
Details and a complete list of changes appeared in the September 7 edition of Cruise News Daily.