Costa Concordia

Forget black cats, broken mirrors and unstoppable psychopaths in hockey masks -- on Friday the 13th, the biggest terrors sometimes hit our wallets. No, the Great Crash of 1929 didn't start on a Friday, but a fair number of financial disasters did.

Maybe it's time for Carnival to beach its Costa brand. The cruise line suffered another ugly mishap this week when a fire aboard the Costa Allegra left the ship powerless on the Indian Ocean, stranding passengers for three days with no hot food, air conditioning or running water.

In the Mediterranean waters near Giglio, treasure hunters are preparing to dive after the lost loot of the Costa Concordia. But the riches that went down with that cruise ship pale next to what one wreck hunter thinks he's found off the coast of Massachusetts: $3 billion in platinum.

It's now been two weeks since the Costa Concordia accident off the Tuscan coast of Italy. That tragic event aside, cruising is still a remarkably safe vacation choice. What's probably not as safe is investing in Costa's parent Carnival.

Last weekend's Costa Concordia accident, when the Carnival luxury liner tipped over after running aground on a rock off the Tuscan coast, was a thankfully rare tragedy. But even one such event is enough to scare some people away from floating vacations. If you're not one of the skittish, that temporary slowdown in bookings is just one reason this is a great time to schedule a cruise.