It's ironic that Carnival (NYSE:CCL) owns Princess -- the cruise company best known for the cheesy 1970s Love Boat show -- because "It's complicated" is the best way to describe the market's tenuous relationship with the slumping cruise line operator.

Save us, Charo!

In a move that shouldn't surprise anyone who hasn't been stranded at sea for the past few months, Carnival is hosing down its guidance. Its stock is taking in water on the news.

Forced into discounting to fill its cabins, net revenue yields are coming in lower than the flat guidance it had provided earlier this year. Toss in a few cancelled sailings since the company's most recent financial update and the increased promotional costs to make folks forget about all of the negative headlines and profitability is taking a pretty big hit.

Carnival now sees earnings of $1.45 a share to $1.65 a share this year, well off its previous guidance calling for as much as $2.10 a share in net income.

For now, the rest of the industry is in good shape. Norwegian Cruise Line (NYSE:NCLH), Royal Caribbean (NYSE:RCL), and Disney (NYSE:DIS) hit 52-week highs earlier this month. Steiner Leisure (NASDAQ: STNR) -- the spa operator pampering passengers on 156 ships across all of the major cruise lines -- opened yesterday at a new 52-week high.

The investing mind-set appears to be that crisis at Carnival spells opportunity for the smaller operators. It's a fair approach, but what about all of the discounting? Plenty of potential passengers are having second thoughts about cruising in light of Carnival's notorious mishaps since last year. If Carnival is marking down its vessels to appeal to the thinning number of interested travelers, will NCL, RCL, and Disney really be immune?

Investors need to be careful here. Carnival stock is trading lower this year -- and understandably so -- but it's naive to think that Carnival is either going under or that its rampant discounting won't force its peers to at the very least be more promotional in the near future.

If a rising tide lifts all boats, what does a falling tide for one boat do to the other cruise ships at sea?

Photo: Rick Munarriz goes tubing in Jamaica on a shore excursion during his last Carnival cruise. He's not the only one taking on water these days.

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.