If you purchase hard liquor in a port, you must turn it in when you reboard to be held until the last day.
Then, you pick it BEFORE you get off the ship on debarkation morning to take home.
The basic alcohol policy is each adult 21 and over may bring onboard 2 bottles of wine/champagne (750 ml max) OR 6 beers (12 oz max each). This allotment may be brought onboard on embarkation as well as from ports of call.
Hard liquor is not allowed to be brought onboard for personal consumption. But will be held for you until the cruise is over.