Purchasing prepaid cards for a cruise may or may not be a good deal. We just got off a HA cruise and we were discouraged from purchasing a coffee card by a crew member. The reason was that depending upon your drink you may actually pay more per drink using a coffee cruise card. We also took a look at the drink card and decided it was better to purchase a bottle of wine at dinner and have the steward bring the unused portion back for the second evening. Some travelers may think that is a hassel and would prefer a card. I think this is just a personal decision. By the way--drink cards are available the day you board. Just ask any staff person. You will usually find them close to the elevator being used for passengers who are embarking.