Seeking to raise billions by issuing new stock and securing fresh debt, Carnival (CCL 2.45%) landed some big investors by baiting the hook on its bond offering with a 12.5% coupon rate, according to Bloomberg. That record-setting yield attracted so much interest that the cruise line operator decided to raise its bond offering from $3 billion to $4 billion.

Originally, the company planned to issue bonds denominated in both dollars and euros to appeal to American and European bond investors. However, a massive influx of dollar orders -- the total order book hit $17 billion -- caused Carnival to drop the euro bond sale, issue the additional dollar notes, and cut the dollar coupon rate to a still impressive 11.5%. That's the same rate the euro bonds would have come with.

The Carnival cruise ship Pacific Dawn.

Image source: Carnival Corporation

Cruise lines, whose vessels are sometimes described as floating petri dishes, have been particularly hard hit by the pullback in travel caused by the COVID-19 pandemic. Carnival, like most of its peers, has put a hold on new cruises for now, though some of its vessels are still at sea with passengers on board.

Carnival says that it needs $1 billion monthly to continue operating, even if it's not catering to passengers. It costs $2 million to $3 million per month to maintain a temporarily decommissioned ship in a high state of readiness to be brought back into service. It could reduce that cost to $1 million a month per vessel, but that would make the process of getting those 100-plus ships back into service once conditions allow for it more difficult and time-consuming.