You are right, I just looked it up:
On embarkation day, each guest of drinking age may bring one (1) sealed 750 ml bottle of wine or champagne. Boxed wine and other containers are prohibited. Guests who purchase alcohol bottles onboard, in a port-of-call, or bring more than the one permitted bottle on boarding day, will have their items safely stored by the ship. These bottles will be returned on the last day onboard for enjoyment once home.
For consecutive sailings, guests of drinking age are allowed to bring one (1) 750 ml bottle of wine or champagne for each individual sailing. Additional bottles will be stored by the ship and delivered, one bottle at a time, to the stateroom on the first day of each new voyage.