2020 was a wild year for Norwegian Cruise Line Holdings (NCLH -1.60%) stock, starting out strong, then succumbing to an 83% decline between February and March as the coronavirus pandemic took hold, and finally ending the year down 58%.

But here's the silver lining for investors: Buy Norwegian Cruise stock now, and if the share price just goes back to where it was a year ago, you will more than double your money.

Or so the thinking goes.

And that may be thinking right. But what are the chances of it happening?

Cruise ship at night

Image source: Getty Images.

The smallest of the big three publicly traded cruise lines, Norwegian Cruise stock currently carries a market capitalization of only $6.7 billion. Over the five years preceding the pandemic, it averaged profits of about $740 million per year, according to data from S&P Global Market Intelligence. If you assume that at some point in the future things will get "back to normal" for Norwegian (and I do), then the stock therefore costs just nine times normalized earnings.

That's less than half the 20.8 P/E ratio the stock has averaged over the five years preceding the pandemic. And it suggests that there really is a case to be made for Norwegian Cruise stock doubling once things get back to normal.

The bigger question is how long it will take to return to normal, and whether Norwegian has enough cash to survive until cruising resumes, so it can get back to making the kind of profit it used to make.

And here's the thing: After running the numbers on Norwegian Cruise stock, I estimate the company has something on the order of $3.6 billion in cash available to it right now. Even at a monthly cash burn rate of $175 million, this implies that Norwegian has sufficient cash to keep itself afloat through about September 2022 without needing to sell any more stock or take out any more loans.

Will that be long enough? The best estimates I've seen suggest cruising in the U.S. won't start up again before April or May -- and even those cruises will be of limited duration and with limited passengers onboard. We can't expect "normal" to return completely, though, until vaccines have been widely distributed across the U.S., and experts aren't expecting that to happen before summer.

Still, even if cruising isn't back to normal before the end of this year, the worst should be over by September 2022, when Norwegian runs out of cash. If you can afford to be patient, I see a real opportunity to earn a double on Norwegian Cruise stock within the next couple of years.