Like Flowers said, some ships have it, but most don't. I've used it once, and frankly, I LOST the paper certificate. It took several phone calls, but they did "find" my certificate in their files, and allowed me to use it. IMO it's GREAT, but not as good as the Princess plan. Wish they'd adopt the "Princess Plan" on this deal, as it's much easier, and offered on every Princess ship I've sailed lately. Good luck. (I'm sailing "Liberty" soon, so I hope that ship offers the certificates!)
"SKY"