Cruise stocks are absolutely surging today. Whether investors are looking at Carnival (NYSE:CCL), Royal Caribbean (NYSE:RCL) or Norwegian Cruise Line (NYSE:NCLH), gains of between 4% and 8% are in order during the Tuesday session.Given that we’re still in earnings season, investors may be correct in assuming earnings have something to do with this move. Carnival reported second-quarter earnings which surprised the market and analysts, showing a quarterly profit of 11 cents per share on revenue of $5.78 bill ...