To get upgraded on Carnival, watch for Carnival room upgrade offers sent by email or check the “Upgrade” section in your booking online. You can also ask your travel agent or contact Carnival directly about available Carnival Cruise room upgrades. Sometimes last-minute carnival cabin upgrades are offered at check-in, but they aren’t guaranteed. For help or to explore upgrade options, ... https://www.cruisesfares.com/blogs/how-to-get-upgraded-on-carnival-cruise