We only bring on champagne and wine which IS allowed on Princess for private consumption,which we brought from home wrapped carefully as carryon on the flights.. ....For Diet Pepsi..in San Juan... we went to the local Walgreens, downtown walking distance from The Wyndham Condado where we stayed.. for 2 -12 packs of diet pop for DH Mark,(cost $7.00 ..).hand carried that on with our carryon luggage..what Princess passengers can do..is order a gift package of liquor gifted to yourself to your room... and send it to themselves online prior to sailing..=shrug, we do not drink enough to make a difference, I have an occasional glass of wine or small drink of the day..:cheers..Joanne