What happened

Cruise ship stocks fell on Tuesday after reports of more voyage delays surfaced. By the close of trading, shares of Royal Caribbean (NYSE:RCL) and Norwegian Cruise Line Holdings (NASDAQ:NCLH) were down 4.9% and 5.3%, respectively, while Carnival's two stocks Carnival Corporation (NYSE:CCL) and Carnival Plc (NYSE:CUK) were down 6.7% and 5.3%.

So what

Carnival said late on Monday its new Mardi Gras ship will not enter service until Feb. 6. It was originally scheduled to set sail in November, but the coronavirus pandemic is forcing the company to alter its plans. Carnival was thus forced to cancel all of the ship's planned departures until the end of January. 

A cruise ship is sailing as the sun sets.

Cruise ship stocks sank on Tuesday on news of more voyage delays. Image source: Getty Images.

The cruise line is also delaying the completion of upgrades to its Carnival Radiance ship until the spring, due in part to COVID-19-related issues. That will result in additional voyage cancellations.

Now what

COVID-19 is making life miserable for the major cruise ship operators. The industry has been plagued with coronavirus outbreaks and corresponding sailing restrictions, which threaten to keep cruise ships stuck at port until the fall -- and perhaps much later.

Royal Caribbean and Norwegian Cruise Line Holdings recently formed a panel of health experts in an attempt to find a way to safely resume sailing, but it may not be enough. If an effective vaccine or treatment for COVID-19 is not found soon, many people will likely forego booking cruise vacations due to fears of getting sick. With little revenue coming in, cruise ship companies are bleeding cash.

This makes the stocks of Carnival, Royal Caribbean, and Norwegian Cruise Line Holdings risky bets, at least until a medical solution to COVID-19 is discovered.