Most (if not all) ships will not allow you to board liquor (with the exception of wine and champagne in most cases) and will confiscate it when caught trying. Bummer.
Here are some of the suggestions I have heard (even though I do not drink hard liquor)
Fill a water bottle with vodka, tequila or gin
Fill a coke bottle with scotch or bourbon
Carry on a gift wrapped bottle of booze as a bon voyage gift.
In Hawaii, buy the mini bottle leis and simply wear them onto the ship.