Cruise Ship entertainers are usually on their way "down" instead of on their way "up."
rarely have I seen an enertainer get popular where I can say "I used to see him on cruise ships." Although I believe there are a few stars out there who do say they did cruise ship stints when starting out.
I am guessing you will see more & more as time goes on, because there are so many more ships now and entertainment on ships is finally starting to really target a younger audience.
I am the editor, but I also speculate, ask questions and play devil's advocate. I reserve the right to change my mind.