We are going on an extended cruise - the drink packages are way too expensive - we like a glass of wine at dinner, and on sea days may spend some time up at the Crow's Nest Bar. However I noticed that HAL has drinking cards that we can buy up to a maximum of $250. Do they work like a debit card? Can I use them for alcohol, wine, specialty coffees and soda (i.e, 7up, Sprint)? Can we purchase additional cards on board? If I buy before we board, will they be left in our cabin upon our arrival? I did a search first before posting and it came up with nothing hence I'm asking here. Many thanks for any information you can provide.