Been worrying about the carbon footprint of your gas-guzzling mega-yacht? If only ... But for those in such an enviable position, there's a solution in the form of a new fleet of catamarans which, though fitted with every conceivable luxury, are wind-powered. They start at £8,600 a week for the 56-foot Blue Note, sleeping eight, from SLM Group: 0845 257 2772.