The fickle fate of finance has clubbed yet another maritime niche, one that has been an overachiever for much of the past decade. The cruise industry, riding high for more than half a decade, was dealt a dose of reality last week when shares of the two top companies, Carnival Corp. and Royal Caribbean Cruises, were dragged to new lows after Carnival issued a financial report. The problem: profitability, a condition not easily remedied considering a decidedly toned down outlook on cruise passenger numbers for the remainder of the year and a record amount of new tonnage still contracted to come on line in the next several years. Executives of the Miami-based operator of the Carnival…