I'm not Jewish, but I'd love to take a Kosher cruise. The food would be great, because it's absolutely fresh, and prepared carefully. I'd also love to hear the classes and lectures the rabbis give during these cruises. I've also heard of Passover cruises, where Seder meals are offered, and I'd love to participate in one of these services.
A Kosher cruise would be one of learning -- and I love to learn new things.