Extract from UK T&Cs re Company making changes
In the event of a significant alteration prior to departure of an essential term of the Cruise, the Company will inform you of any cancellation or change of itinerary in writing as soon as reasonably possible and you will be offered a choice of:
i) accepting the alteration; or
ii) booking another Cruise of equivalent or superior quality, if available or booking another Cruise of a lower quality, if available, with a refund of the difference in price; or
iii)cancelling and receiving a full refund of all monies paid.