Carnival Cruise Lines needs to learn that.
Read more: http://www.cnn.com/2013/03/14/travel/cruise-ship-trouble/index.html?hpt=hp_t3
That's not too disastrous if they are dressed up in pretty uniforms and only do things like wait tables and make up beds. But you can't hand them a miocrometer and tell them to check the wear on a critical bearing or shaft in a generator.
You can't keep a 100,000 ton liner running properly with a maintenance crew that consists mostly of low paid should-be farm workers. A ship may have a highly trained and educated individual in charge of the ships engines, generators, pumps... all those tricky and complicated gadgets that keep a ship alive... but the grunt level mechanics are about as proficient as a cowblood-drinking primitive.
That's why these ships have failing systems. Their maintenance people are the equivalent a bunch of untrained monkeys, generally shirking off preventative maintenance and then falsifying the records about what they did... or didn't do. Not all of the ships, but which ones are quite obvious.
Paint them white, make them all pretty and shiny, but if the maintenance crew looks like it wants peanuts and bananas for lunch - and thinks that a crescent wrench is something the moon does occasionally - don't get on board.
This is going to continue until the cruise line owners realize that ship maintenance requires skilled technicians and craftsmen, not a bunch of underpaid ignorant idiots under the leadership of some overpaid college-trained "expert".