Investors who nailed the bottom in cruise line stocks are sitting pretty these days. Carnival (NYSE:CCL) (NYSE:CUK) has soared 78% as of Monday's close since bottoming out in early April. Royal Caribbean International (NYSE:RCL) and Norwegian Cruise Line Holdings (NYSE:NCLH) hit their lows in mid-March, shortly after docking their fleets. Since then, Norwegian Cruise Line has risen 67%, and it's the laggard of the lot. Royal Caribbean has nearly doubled, leading the pack with a 98% bounce. 

It's easy to assume that the worst, like a losing night at a floating casino or eating some bad sushi from a midnight buffet, is in the past. But there are still a few things that are far from settled at the three publicly traded cruise line operators. Let's see what needs to be resolved before we can really start calling this a turnaround. 

Sapphire Princess sailing on blue waters.

Image source: Carnival.

1. Crew members are still stuck on ships 

It's been two months since the last new cruise set sail and several weeks since the last of the quarantined passengers were allowed to go home. It's a different story for the folks working on the ships. There were as many as 100,000 crew members across all three cruise lines stuck on their ships earlier this month, imprisoned by the inability of the cruise lines to agree with the U.S. Centers for Disease Control and Prevention on repatriation. 

Things aren't getting any better now that a couple of crew members have died, including one apparently by suicide. Royal Caribbean had signed a deal to send crew members home by May 16, but several crew members of one ship went on a hunger strike after that date got pushed further out. If you think passengers have horror stories and lawsuits in the works, just wait until the crew members get their turn. 

2. Rosy reports have been misleading

A report over the weekend (breaking on celebrity gossip hub TMZ of all places) claimed that Carnival bookings were up 600% since announcing last week that it would resume some of its sailings in August. This would seem to be a spectacular development on the surface, but obviously there's a lot more to that story.

The source here was a privately owned travel-agency franchise network, and it was comparing booking activity with the level of interest three days before Carnival's announcement that it would start sailing again on Aug. 1. The industry standard for booking reports is to compare where year-to-date activity is relative to a previous year, so comparing three days before to three days after is silly. It also needs to be emphasized that Carnival announced last week that just eight of its more than 100 ships will begin sailing in early August, and even those sailings are still vulnerable to cancellation if the industry's no-sail order isn't lifted. 

This isn't the first time that a "too good to be true" report from an indie travel agency source didn't hold up as something that can be extrapolated across the industry. Last month, The Los Angeles Times (a steadier source for financial news) quoted the operator of an online cruise marketplace as seeing a 40% increase in bookings for next year over the previous 45 days relative to where activity was a year earlier. The CEO of the agency would go on to clarify that the metric was misinterpreted. The number was simply the mix of far-off sailings relative to last-minute bookings. Bookings for next year were actually 23% below the prior year's pace. 

3. We still don't know what cruising will be like

Cruise lines don't technically have the green light to start sailing, and we still don't have guidelines for what the experience will be like. We know some cruise lines are canceling upcoming trips for anyone older than 70 without a physician's note clearing them as fit to travel. 

Cruise line executives have offered few details as to how the cruising experience will be in the future, but with social distancing likely to stick around for the time being, the requirements could be substantial. It's highly unlikely that buffets will be available when ships start sailing again. And executives have discussed limiting passengers to just exterior berths with access to fresh air, or filling just every other cabin to space out its customers. Will masks or other passenger safeguards be required? When cruise lines start sailing again, the profitability isn't likely to be the same for Carnival, Royal Caribbean, and Norwegian Cruise Line. The passenger experience will also be different until we're over the COVID-19 crisis. 

The news isn't all bad. All three cruise lines have shored up their financing to survive near-term liquidity concerns. Although the stocks have nearly doubled since their lows, it still finds them well below their previous highs, so the upside is still there if things get back to normal quickly. But for the current rallies to continue, they must clear some big hurdles in the coming weeks. No one said investing in cruise line stocks would be easy. 

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.