Cruise stocks are surging nearly across the board today after Norwegian Cruise Line (NYSE:NCLH) lifted its full-year earnings outlook on strong demand.What’s up with cruise stocks today?Well, the likes of Norwegian, Carnival (NYSE:CCL) and Royal Caribbean (NYSE:RCL) are up 7.5%, 7.2%, and 4%, respectively, heading to the bell. It seems the cruise operators are benefitting from changing tides in the cruise industry, as well as general bullish momentum in the stock market as a whole.Indeed, Norwegian told ana ...