By Daniel Kline Carnival Cruise has a big surprise for its fans and investors (and maybe delivers a perfect day). You can’t watch television without seeing ads for Royal Caribbean (RCL) – Get Royal Caribbean Group Report. The cruise line has been one of the top travel brands on TV. Many of those ads feature images from CocoCay, the company’s reimagined private island in the Bahamas. The island has completely changed the cruise-line-owned destination game. Whereas private islands have generally been beaches that offer lunch, drinks, and maybe a gift shop, CocoCay offers multiple beaches, the la…