Did you book two to a cabin meaning two cabins? If so the single cruiser will be charged the full price just like there was still double occupancy. You can change the name from person not going to someone who is willing to go before the PIF date 90 days out (maybe closer also). Some Ships have a limited number of studio cabins designed for a solo traveler if the two cabins don't have to be adjoining but might not be much cheaper. Knowing beforehand that it will only be one person and the price will be the same as it was booked, just show up with the one person and the taxes and port fees for the ( No Show) should be refunded after the cruise. I believe if you went this route, the single cruiser would get double C&A Points for the cruise?