The two biggest players in the cruise industry -- Carnival and Royal Caribbean -- have both generally performed well. The two companies, however, are in a bit of an arms race -- adding new ships with increasingly impressive features -- think ice skating rinks, laser tag, and robot-run bars just to start -- when questions exist as to whether younger people will want to cruise. Both companies have taken steps to market to younger generations and, so far, the numbers look good but as is the case on any cruise, a storm could be coming.