Carnival's (NYSE:CCL) image has suffered in a big way due to the 2012 Costa Concordia sinking and the 2013 Carnival Triumph being adrift at sea for five days with no running water or air conditioning. Despite the norovirus spreading on the Carnival Princess not being the company's fault, it didn't help the company's reputation, either. However, what's done is done. Is Carnival now capable of a turnaround, or is there a better investment at sea?

By the numbers
If you ignore expectations and look at the actual numbers, Carnival's first-quarter non-GAAP net income came in at $2 million; this was considerably lower than last year's net income of $67 million.

For the second quarter, Carnival expects net revenue to decline between 3% and 4% year over year, and for net cruise costs to increase between 2.5% and 3.5%.These aren't the types of numbers investors like to see. 

Looking ahead to fiscal year 2014, Carnival expects volumes to increase almost 20% worldwide, which is partially based on more customers booking in advance. While this might seem like a positive, this trend is primarily driven by lower prices. Therefore, additional volume may come at the expense of some reduced revenue and profitability.   

The biggest thing Carnival has going for it is that it's a good value option for hesitant consumers looking to go on a cruise. The best way for Carnival to get back on its feet is to deliver high-quality customer service for an extended period of time. Carnival's competitors find themselves in a much different boat.

Appealing versus expensive
Norwegian Cruise Line (NYSE:NCLH) is the newest public company of the bunch; therefore, it generates a lot of excitement. Despite that excitement, the stock has only seen pedestrian stock appreciation of under 10% over the past year -- during a raging bull market. Over this same time frame, Carnival and Royal Caribbean (NYSE:RCL) have enjoyed stock appreciations of 15% and 68%, respectively. It's somewhat surprising that Carnival has outperformed Norwegian Cruise Line over this time frame, but many investors have looked at unfortunate Carnival events as in the past, providing a value opportunity to invest in the largest cruise line in the world. However, if you're looking strictly at numbers, then Norwegian Cruise Line appears to offer more potential.

Looking forward to fiscal year 2014, Norwegian Cruise Line expects net revenue to increase 4% on a constant-currency basis, with net cruise costs expected to decline between 2% and 1%. This should catch the eye of any investor.

Norwegian Cruise Line's launch of Norwegian Breakaway and higher pricing aided the top line in 2013, which has the potential to carry over to 2014. However, Norwegian Cruise Line is trading at 66 times earnings, making it more susceptible to downside moves on negative news than its peers.

As for Royal Caribbean, it expects fiscal year 2014 net revenue yield to increase between 2% and 3% on a constant-currency basis, with net cruise costs expected to remain flat or to decline slightly. This might not be as impressive as Norwegian Cruise Line, but Royal Caribbean is seeing high demand in Europe and Asia, on-board revenue continues to increase, and the stock is only trading at 26 times earnings -- cheap compared to Norwegian Cruise Line.

The Foolish bottom line
While it's possible that Carnival will surprise the street in the future, with net revenue expected to decline and costs expected to increase, this doesn't appear to be an attractive investment at this time.

Norwegian Cruise Line and Royal Caribbean have higher expectations going forward, which should make these cruise lines more appealing to investors. While Norwegian Cruise Line is sailing at the fastest speed on the top line, valuation is a concern. Royal Caribbean offers growth potential as well as the possibility of reduced costs while trading at a fair valuation, which means less risk. Please do your own research prior to making any investment decisions.