Most of Carnival Cruise Line's ships would sail to Celebration Key, the company's private resort-like port set to debut in July 2025, as shown in a render.Carnival Cruise LineCarnival Cruise Line's new $600 million private port, Celebration Key, is set to open in July 2025.Most of Carnival's ships will sail to the resort-like destination.Cruise line-run private islands have been big moneymakers for companies like Carnival and Royal Caribbean.