Nearly half a dozen cruise ships scheduled to return to Florida on Sunday or early today remain at sea due to Tropical Storm Isaac.

Industry giant Carnival says the closure of the port of Miami since late Saturday has forced the 2,974-passenger Carnival Valor and 2,052-passenger Carnival Imagination to delay their return to the city. Also delayed returning to Miami are Royal Caribbean’s 2,350-passenger Majesty of the Seas and Norwegian Cruise Line’s 2,004-passenger Norwegian Sky.

The lines say they expect the ships to return to Miami later today after the port reopens and depart on their next voyages this evening.