Louis Cruises announced back in August 2014 that it would be launching a new brand the following month. By November two of the ships in the Louis Cruises fleet had transferred to the new subsidiary brand Celestyal Cruises, namely the Piraeus and Lavrion based 25,611gt/1980 built Louis Cristal and 37,773gt/1982 built Louis Olympia, ready for the 2015 season.

Louis Cruises will continue to operate cruises and its ship management and chartering business. The name of the new subsidiary is in honour of the Ancient Greeks, who were among the first people to use celestial navigation. On 20th November Louis Cruises added a third ship to the brand in the form of the Semester at Sea ship Explorer. The 24,318gt ship was built in 2001 as the Olympic Explorer for Royal Olympic Cruises by Blohm+Voss in Hamburg. A renaming to Olympia Explorer followed before assuming her most recent role as the Explorer. The 840 passenger ship, capable of 28 knots, will operate Aegean itineraries from May 2015.

As of 25th November Semester at Sea was on the hunt for a replacement vessel, to charter rather than own. The Explorer will complete her educational duties with the spring semester, sailing from San Diego in January 2015, disembarking in Southampton on 29th April. Her sister vessel, built as the Olympic Voyager, was sold by Costa Cruises to Chinese interests earlier in 2014.