The deal gives any adult who paid the full fare of a twin inner cabin the option to invite another guest to travel with them for free, writes Alexandra Marill.
It applies to all CMV cruises departing in 2018, including the 121-night Columbus Round the World cruise, departing on January 5 and the 6-night Magellan Cruise leaving from Bristol on October 22.
The only cruise to be exempt from the deal Arctic and Greenland Expedition Voyage on board the Marco Polo at the end of July next year as it is more than 90% sold already.
