There’s still plenty of smooth sailing ahead for some of the top cruise stocks to buy.Carnival (NYSE:CCL), for example, just raised its full-year earnings outlook after strong demand for cruises helped it post a surprise profit. Royal Caribbean recently boosted its full-year profit forecast as cruise demand surged, prompting price hikes. Companies like Norwegian Cruise Lines (NYSE:NCLH) also reported record bookings thanks to booming demand. In addition, “The demand for cruise vacations continues to be at a ...