When you think about a cruise, there is a good chance you picture an elderly couple slowly climbing the steps to a big boat that will slowly sail along to warm and sometime exotic locations.  Your think that it will be a boring and lazy trip that is perfect for your grandparents.  You also fear that these will probably boats rock wildly and run the risk of careening headlong into hurricanes while you are tossed from one side of the ship to the other. Finally you think that there will be nothing to do on these ships, so in between…