A notice has gone up on Marella's cruise noticeboard asking passengers to stop hiding rubber ducks around the ship and to leave cabin doors bare. It's politely worded, complete with a duck pun, but the message is clear enough. Ducks left around the ship or at the ports will be picked up and binned, and anything stuck to a cabin door may be taken down by the crew. If you've never come across cruise ducks, the idea is simple. You buy a bag of small rubber ducks, tag them with y