Thanks for the link dramachic5191. There have been several posts about cruise ships, check out the search feature and you should find some good information. The two things I know to watch for are what are the 'other duties' assigned, and what are the restrictions of being crew. I've heard of some lines that you're pretty much barred from any of the 'fun' sections of the ship because you're crew and not to interact with guests. And be prepared to do more than just SM - not sure if I've heard of any cruise line that has just SMs, they usually double as another tech position.
-Centaura